COM Port Redirector Help Center

It is not possible for the DialOut/EZ redirector to emit the sounds that the modems are making during the handshake at the beginning of a call.

A modem is able to emit modem sounds itself, but there is no mechanism that can relay the sound up to higher-level hardware.

When a modem is used by a redirector across a network, any sounds are available only at the modem's location and not at the computer running the redirector. The only information about the negotiation that the redirector receives is via the data interface to the modem, such as CONNECT, NO ANSWER, NO CARRIER, and NO DIALTONE.

These messages can be viewed in real-time in the Trace tab in the redirector's Port Monitor window.

Although modem servers can be used over a VPN for nearly all applications, this specific configuration does not work due to an inevitable conflict in handling of the IP routing table.

The redirector needs to be able to connect continuously to the modem server. PPP/DUN connections disrupt this connection when they change the default route.

The redirector must adjust the routing table to maintain a connection to the modem server VPN software does not permit adjustments of the routing table, for security reasons. Other types of dial-out applications are not susceptible to this problem and operate successfully with modem servers over a VPN.

Yes, with two exceptions:

If you are using a Citrix server, the operating system prevents the use of more than one such connection.

If you have used a VPN to reach the network containing the modem server, you can not make another VPN connection (e.g., PPP or dial-up networking connection) using a modem on the modem server.

Yes.

Uninstall the software from the old computer, through the Windows Control Panel.

Install the software on the new computer, using the latest version of our software from the Downloads section on our web site.

During installation enter the license key when prompted or enter it afterward by clicking on the Licensing button.

Serial/IP and COM/IP differ as follows:

COM/IP is a modem emulator, used when an application dials phone numbers on a Windows modem device, but needs to connect to an IP endpoint.

Serial/IP is used when an application that opens COM ports needs to connect to an IP endpoint.

Therefore, if your application opens a COM port, use Serial/IP. If it needs to dial a phone number, use COM/IP.

Yes, VMware is supported as a platform.

Tactical Software redirectors can be installed on the virtual machine, or on the guest machine.

Click this link to go to the Quick Start section of the Serial/IP User Guide

Click this link to go to the Quick Start section of the COM/IP User Guide

Click this link to go to the Quick Start section of the TacServe User Guide

Click this link to go to the Quick Start section of the DialOut/EZ User Guide

No.

All Tactical Software redirectors are kernel-level device drivers.

The TacServe Modem Pool Server and License Manager run as Windows Services.

Consequently, no user needs to be logged in for the products to operate.

In the COM/IP, DialOut/EZ and Serial/IP Seat Edition clients, you will find the license key by clicking the Licensing button on the product's Control Panel.

The DialOut/EZ and Serial/IP TacServe Edition clients do not use license keys or have a Licensing button on their Control Panel.

The DialOut/EZ Site Edition client does not use a license key, but instead accepts the IP address of the License Manager machine by clicking its Licensing button.

The DialOut/EZ License Manager's license key can be accessed via the License Manager MMC by selecting Action | Licensing or right-clicking the DialOut/EZ License Manager icon and selecting Licensing.

TacServe's license key can be accessed via the TacServe MMC by selecting Action | Licensing or right-clicking the TacServe COM Port Server icon and selecting Licensing.

If the license key is not accepted by a Tactical Software product, please check the following potential problems:

Verify the license key is for the correct product and version being installed. License keys are not compatible across products or major version numbers. Point releases do not require a new license key (i.e. updating from 4.9.7 to 4.9.12).

Verify that the license key is not an evaluation or timed key that has expired.

Administrator rights may be required to enter the license key.

Tactical Software products work in evaluation mode for 30 days without a license key. After this time has passed, a license key is needed to restore operation. If more time is needed to evaluate the Tactical Software product, contact your sales representative to discuss an extension of the evaluation period.

If the above suggestions do not help, please email support@tacticalsoftware.com

Login to the machine with administrator rights during installation.

Modification of the COM port settings may require administrator rights, if such rights are required to edit the HKEY_LOCAL_MACHINE/Software/ registry section on that machine.

If the redirector's Control Panel interface doesn't open, then the software was installed in Administrator Only Mode. Login as an administrator to configure the software.

Tactical Software products use the Microsoft Installer and support unattended installation.

Tactical Software Technical Articles - Unattended Installation contains the information on this feature.

All versions of Microsoft Windows which support IPv6 are dual stack, meaning they can operate in both IPv6 and IPv4 networks.

Tactical Software has successfully tested its products in a variety of network environments and Windows versions which include both IPv6 and IPv4 addressing.

Tactical Software's products are deployed in environments with devices that support IPv4-only. Many of these devices are legacy systems which will never support IPv6. The few devices that support IPv6, do so in addition to IPv4, maintaining backward compatibility. Anyone upgrading their network to be IPv6-compliant will not encounter issues with Tactical Software's products, as IPv4 connectivity will still be needed for many other devices and software on the network.

While updating to a IPv6-based network is mandated or needed in some cases, these networks will be required to also support IPv4 for the foreseeable future. Until the last device and piece of software that requires IPv4 is removed from a network (including any external devices/systems that interact with it), there will be a need for the network to support IPv4 in addition to IPv6.

Therefore, Tactical Software will not be incorporating direct support for connecting to network endpoints using IPv6 addresses and has decided to continue using IPv4 in its products. Our products will continue to require that network endpoints be specified using IPv4 addresses, or hostnames which resolve to IPv4 addresses.

Yes.

The COM/IP Redirector can be used to convert modem-based applications to use serial device servers.

This eliminates the need for modems at either end, while preserving modem behavior expected by the application software.

No, they are independent from each other.

The License Manager PC's firewall will need to be configured to accept incoming connections on TCP port 2392.

Also, there can not be a NAT between the DialOut/EZ Site Edition client and License Manager.

No, the modem drivers should work fine.

In many cases the modem drivers can not be signed as the certification process involves testing the drivers with dial-in to the modem, which some modem servers do not support.

In other cases, the modem drivers were written before the current version of Windows was released and the drivers are no longer being updated.

Yes, if the modems on the server are fax modems that support Class 2 or Class 2.0 fax and the PC faxing software is set accordingly.

Class 1 fax modems are too sensitive to data latency to be used reliably with any redirector.

Yes. DialOut/EZ can be used to receive incoming calls.

This requires that one modem on the server will be in use by the application while waiting to accept the incoming call.

Any model of modem that connects to a hardware COM port or creates COM ports in Windows will work with TacServe Modem Pool Server.

The only requirement is that the modem must be able to connect to the endpoint. For example: If the remote modem requires a V.22bis connection, make sure that the modem in the TacServe PC supports V.22bis connections.

For large TacServe configurations, Tactical Software recommends the following modem cards:

Analog: Comtrol RocketModem (4 and 8-port models) and the Multi-Tech MultiModem (4 and 8-port models).

Digital: Dialogic DivaServer (formally Eicon DivaServer), configurations range from single to multiple T1/E1s per card.

If you have any questions, please contact Tactical Software Support at support@tacticalsoftware.com

The following modem servers are known to work with DialOut/EZ:

Cisco 2xxx, 3xxx, AS5xxx with modems

Tactical Software TacServe Modem Pool Server

There are several older modem servers that work with DialOut/EZ, such as Digi 7000 Series, Lucent APX1000 or TNT, MultiTech MultiAccess, MA100-1M, or CommPlete, and UTStarcom Total Control.

Tactical Software recommends creating a modem server using a Windows PC, one or more modems, and TacServe Modem Pool Server software.

TacServe has enterprise-class features and administration not found in traditional modem servers, and is easily scalable to multiple T1/E1 modem cards.

For more information, please see the TacServe Modem Pool Server product page or email Tactical Software Support at support@tacticalsoftware.com.

Basic Setup

Cisco IOS version 12.1(8) or greater is required.

The client machines will need to have the correct modem drivers installed. Please contact support@tacticalsoftware.com for the modem drivers.

The IOS configuration under the 'line' section of the configuration file should be:

line "begin" "end" ! replace "begin/end" with first/last lines
modem inout ! if dialout ONLY, use "modem dtr-active"
transport input telnet
modem autoconfigure type mica rotary 1 ! use TCP port 7001 to dial out rotary 1
AS5350 note: Make sure the line "escape-character NONE" is in the Line Config.

DTMF Data

Cisco routers with digital modems require that an "X" character be placed in front of any DTMF data (dual tone multi-frequency) that is sent in a dial string after a phone number.

To dial the phone number 1234567890, pause for 15 seconds and then dial 12345, the dial string needs to be 1234567890X,,,,,12345

However, this may create another issue. Microsoft TAPI can strip out characters in a dial string and in some cases the "X" character can be removed.

For example: In HyperTerminal, go to File | Properties and uncheck the "Use country/region code and area code" checkbox. Now when a call is made the "X" character will be sent through. When this box is checked, HyperTerminal will remove characters (including the "X") that it doesn't consider to be part of the phone number.

Answering Incoming Calls

Cisco routers with digital modems (Mica, NextPort) are not able to support dial-in back through DialOut/EZ, as they are not able to answer an incoming call while there is an active reverse telnet session to them. If DialOut/EZ doesn't have a active reverse telnet session to the modem, then the application on the user's PC can not see that the modem is ringing and thus can not answer it.

Receiving an inbound call with a Cisco router that has digital modems is possible with Tactical Software's COM/IP program. Please note that DialOut/EZ is still required to make outbound calls.

The first step is to configure the Cisco to make a raw TCP/IP connection to a PC when the call comes to a specific modem.

Example: If PC's IP address is 10.0.0.1 and the TCP port will be 7000. The configuration on the Cisco router to accomplish this on line 1 is: autocommand telnet 10.0.0.1 7000 /stream

This would make the Line Configuration:

line 1
modem inout
transport input telnet
modem autoconfigure type mica
autocommand telnet 10.0.0.1 7000 /stream
escape-character NONE (if using an AS5350 or 5400)
line 2 40 modem inout
transport input telnet
modem autoconfigure type mica
rotary 1
escape-character NONE (if using an AS5350 or 5400)

For each incoming line redirected through COM/IP, the line "autocommand telnet /stream" will need to be added to a separate line in the Cisco configuration.

On the PC (10.0.0.1) install COM/IP and the COM/IP modem driver. You can download COM/IP from this link.

In the Init String in COM/IP add the string: ATS1008=7000

This tells the COM/IP modem to listen to port 7000 for an incoming connection.

Set the application on the PC to use the COM/IP modem device installed on the COM/IP virtual COM port, and it will receive the incoming call that is redirected from the Cisco router.

Tactical Software COM ports are not displayed in the Windows Device Manager for several reasons:

When a COM port is added or removed, it goes through Plug-and-Play enumeration, which can take 10-30 seconds for each port. It could take several hours to enumerate thousands of ports. Even mid-sized installations would have to wait 30 minutes or more for Plug and Play COM ports to install.

Windows chooses the COM port numbers on enumeration, so users would lose the ability to specify the COM port numbers. This would prevent use of the Serial/IP API and silent-install technologies built into the product.

Avoiding the Windows Device Manager prevents situations for the installer to get stuck or conflict with other drivers. Many of our customers use our product specifically because it avoids the numerous problems with the Windows Device Manager that they have had with other products.

Please note: Even though the Tactical Software COM ports are not present in the Windows Device Manager, any application that uses COM ports will be able to see and use them just like hardware COM ports.

A Trace Log is a log file that shows all the events and data that passes through the virtual COM ports.

Whenever there is an issue reported concerning our software, Tactical Software Support will ask for a Trace Log that shows the issue.

To create a Trace Log: click the Port Monitor button, click the Trace tab, check the Enable Trace box, and then start the application that is using the Tactical Software COM port or modem device. After the session is over, save out the Trace Log with the File | Save As menu item.

Tactical Software redirectors are able to create any virtual COM port from COM1 to COM4096 that is not already defined on the computer. If a certain COM port is not in the redirector's Select Ports list, then it already exists on the PC.

If there is a real hardware port in the system (such as COM1) the real COM port will need to be removed from the Windows Device Manager and then disabled in the PC's BIOS on system boot before the redirector can create an identically numbered virtual COM port.

The following Windows Registry entry shows what COM ports are defined on the system: HKEY_LOCAL_MACHINE/Hardware/Devicemap/Serialcomm/

Any COM ports with the names starting with DISerial, DESerial, CISerial and SISerial were created by Tactical Software redirectors.

To remove any other COM ports, find the process/program that created them and remove them with that program.

Do not delete any COM ports directly from the registry as that may cause serious system problems.

However, COM2-10 on Citrix/Terminal Services PCs can be deleted without any issues.

This error message indicates that a DialOut/EZ Site Edition redirector was unable to contact or otherwise obtain a license from the Tactical Software License Manager.

Troubleshooting procedure:

Verify the license information (License Key, Number of Ports, IP Address) on the License Manager, and that the License Manager shows a non-zero number of licenses at the top (i.e., "0 of 16 licenses").

Reboot the License Manager machine. This is often required after the License Manager is first installed and the License Key is entered for the first time. This will often solve problems if the machine is having any other issues.

Check that the hostname or IP Address of the machine running License Manager is entered into the DialOut/EZ Site Edition client. This is done from the Licensing button in the client's main interface.

Make sure that the PC running the DialOut/EZ Site Edition client can ping the machine running License Manager.

If there is a router or firewall between the machine running the DialOut/EZ Site Edition client and the License Manager, make sure that it is configured to pass TCP connections on port 2392.

Verify there are available licenses. If the License Manager shows "16 of 16 licenses", for example, there are no more licenses.

Ensure that a Class 2 or 2.0 fax is being sent. Class 1 faxes are too time sensitive to be successfully redirected.

Incorrect flow control settings is a common cause for faxing glitches. Typically the modem server is set to Software (Xon/Xoff) flow control and the modem device is set to Hardware (RTS/CTS) flow control (or vice versa).

To correct this, either:

- Change the flow control type on the modem server. The process for doing this will vary depending on the type of modem server.

or

- Change the flow control type on the modem device installed on the PC running our DialOut/EZ client.

This is done from Windows Control Panel | Phone and Modem Options | Modems (tab) | Select your modem device | Properties | Advanced (tab) | Change Default Preferences | Change the Flow Control type.

Verify that the Windows "nslookup" command can resolve the DNS name. If it can't, the Tactical Software redirector won't be able to resolve it either.

Verify that the telephone number is entered correctly (1 for long distance, 8 or 9 for outside line access, etc.).

If the phone number is correct, take out the decimal point (.) separators in the number. Some modems interpret these as pauses and cause the client software to time-out.

Ensure that the line is capable of making outbound or long distance calls.

Verify the correct Windows modem drivers are being used on the COM ports. The virtual COM ports must have modem drivers (usually provided by the modem manufacturer) that match the server's modems.

If the dial-out still isn't working, open a case with the Tactical Software Support group at support@tacticalsoftware.com

Make sure that the most recent version of the Tactical Software product is being used. Most issues that are reported have already been fixed in the most recent release.

If that doesn't help, open a support case with the Tactical Software Support group.

The following serial servers are known to work with Serial/IP:

AAxeon STE, LS, PS and SS Series
Acksys Cometh Advantech EKI and ADAM Series
AETA AECIP Alpha Project SH Series
Alterpath ACS
Atop GW, SE and SW Series
Avocent ESP and TS Series
Axel AX Series
Axis 2490
B&B Electronics ESR Series
BenTek Barionet Cayee VDS Series
Cisco 2xxx, 3xxx, AS5xxx
Centos CI-82500
Comtrol DeviceMaster RTS Conel S.R.O. ER75i (wireless)
CXR TS Series
Cyclades TS Series
DataHunter SeriaLan (wireless)
Data Comm for Business – EtherPath
Digi TS Series Digital Networks
DECserver Cserver
Exemys SSE Series
GarrettCom DX Series
Hirschmann RG2-1TX
HMS Anybus
i-Net Device Comm Assist
IntelliCom NetBiter
Lantronix UDS, Xport and MSS Series
Lucom Lobix ETH
Moxa Nport Series
MRV LX Series
Multi-Tech MultiConnect
Newport Electronics iServer
OpenGear CM4000 Series
Opto 22 SNAP
Patton EtherBITS
Perle IOLAN, JetStream, LanStream
Precidia Ether232Plus, iPocket232, Cell232Plus
ProSoft RLX-FHES
QuaTech SSE, DSE, QSE, ESE and ABSE Series
Rayon GPORT 104, 108 and 116
RuggedCom RuggedServer,RuggedMC
Sarian Systems TA, IR and MW Series
SeaLevel SeaLink Series
Sena LS, PS, SS, and STS Series, IALINK100
Sierra Wireless Raven (Cellular)
SMIC NetEye Series
TC Communications TC3400, TC3847-1 (SSL enabled)
Vizimax, Inc. RightWON Series
Viola Systems ESERV Series
Volktek IRF Series
Westermo ED Series

Please note: If the application or device expects to see serial control signals (DTR, DCD, etc.), then a serial server that supports The COM Port Control Protocol (RFC 2217) is required.

Most hardware Ethernet-to-serial servers can only send data between the application and serial device. In order to send and receive serial control signals (such as DTR and DCD), a serial server must support the COM Port Control Protocol (RFC 2217).

Some serial-based applications and the devices they connect to, expect to see hardware control signals just as if they were directly connected to an RS-232 port. When using these applications and devices, it is imperative that you use a serial server that supports the COM Port Control Protocol. The following serial servers support the COM Port Control Protocol:

Acksys Cometh
Atop GW Series
Axis 2490
B&B Electronics ESR Series
Comtrol DeviceMaster RTS CXR TS Series
Cyclades TS Series, Alterpath ACS
Digi TS Series
Digital Networks DECserver, Cserver
GarrettCom DX Series
Moxa Nport 5600
MRV LX Series
Perle IOLAN
Precidia Ether232Plus, iPocket232, Cell232Plus
Rayon GPORT 104, 108 and 116
SeaLevel SeaLink Series
Sena PS, SS and STS Series, LS110
Vizimax, Inc. RightWON Series

Tactical Software has a software product called TacServe Modem Pool Server, which turns a Windows PC with one or more hardware serial ports into an RFC 2217 compliant serial server.

When using a serial server that supports the COM Port Control Protocol, make sure that Serial/IP is set to Telnet mode under Connection Protocol. The Serial/IP Auto Configure feature will detect and report the presence of the COM Port Control Protocol.

If the Auto Configure does not detect the COM Port Control Protocol when connecting to one of the above devices, make sure that the serial server is configured correctly to accept this protocol.

Any wireless modem (cellular or radio) that accepts incoming raw TCP/IP connections will work with Serial/IP or COM/IP.

Tactical recommends the following wireless modem manufacturers as they are used the most often with no known issues:

Sierra Wireless Raven Series
Exemys Cellular Serial Servers
MultiTech Wireless MultiModems

Overview

Tactical Software redirectors support up to 4096 virtual COM ports in Windows 10, 8, 7, XP, 2016, 2012, 2008, 2003, and 2000 operating systems.

Processor Issues

An application will take more CPU cycles as it uses more COM ports, so it is important to be sure that there is enough processing power for the application to handle using all the simultaneous COM ports.

On most PCs, there is a difference between the ability to have over 4000 ports redirected, and using all the ports at once. It is not hard to max out the CPU of a fast machine with 256 concurrent ports actively passing data, so the ability to use an even larger number of ports will depend greatly on the application behavior and the speed of the host machine.

The application that is being used to open the COM ports and send data creates almost all of the stress on a system, while the overhead from Tactical Software redirectors is almost negligible. Therefore, if an application can use a certain number of real COM ports successfully, then the same results should be seen when using virtual COM ports.

Unless a multi-port test is done with the same application that will be used in a real situation, it isn't possible to tell how many CPU cycles (or how much RAM) it will use, as the specific way that an application is written will determine the resources that it uses.

Some applications take quite a large amount of CPU time per each COM port used, while other programs can transfer the same data using a different protocol with a fraction of the CPU usage.

Networking Issues

A Windows machine will only be able to make 3975 active outbound TCP connections before running out of TCP port numbers. This alone prevents 4096 active COM port sessions, not even counting the fact that other programs will be making their own TCP connections.

The TCP ports used for these connections are not available for re-use until several minutes have elapsed after a connection has been closed. An application which opens and closes COM ports frequently can easily cause the operating system to run out of TCP ports.

There is a registry setting that can be changed to raise the amount of TCP ports available to Windows:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

On the Edit menu, click Add Value, and then add the following registry value: Value Name: MaxUserPort Data Type: REG_DWORD Value: Default: 0x1388 (5000 decimal, (which gives 3975 available ports)); Max: 65534(decimal)

Finding the optimum value for this registry setting will require some experimentation as it is dependent on the serial application that is used and other TCP/IP based programs on the same PC.

Additional Considerations

Tactical Software recommends testing with the same COM port count as needed in the production deployment to ensure the PC has enough RAM and processor cycles to run smoothly. After testing the application successfully with hundreds (or thousands) of real COM ports to be sure that it will not be short CPU cycles or system RAM, keep in mind that the available TCP port range mentioned above must be set high enough so that Windows will not run out of usable TCP port numbers.

Tactical Software redirectors are able to send Trace Log information to a third-party debug application in order to capture large logs files that would normally fill the Trace Log buffer.

The third-party debug application is called DebugView, which is a free application that allows monitoring of debug output on on a PC. It can be used to capture the trace information emitted by Tactical Software redirectors that have been configured to send trace data to the system debug channel.

DebugView can be downloaded from:
https://docs.microsoft.com/en-us/sysinternals/downloads/debugview

To configure Tactical Software redirectors to send information to DebugView, open the Port Monitor, select the Trace tab, under the Trace Options menu select System Debug Output and check the box labeled Send trace data to system debug channel.

In DebugView, check the Capture Kernel option under the Capture menu. DebugView can be used to send the Trace Log data directly to a file by using the File | Log to File command. Otherwise, by default DebugView will fill its buffer with the Trace data and it can be manually saved to a file with the File | Save as command.

If large amounts of data are running through the Tactical redirectors, make sure there is enough disk storage space if writing the logs directly to a file.

Introduction

When troubleshooting an application using a modem or other device, there are three things to consider: the modem or serial device itself, the COM port and cable, and the PC application software.

When a redirector and a modem/serial server enter the picture, the number of potential error sources increases. This technical note suggests a logical approach to the diagnosing problems in this environment.

The Software Modem Cable Concept

A redirector has one simple function: to pass data between a remote TCP/IP connection and a virtual COM port on a client PC.

The analogy of a "software modem cable" is appropriate, as the redirector's primary mission is to pass data and (optionally) control signals between the PC and the modem. When suspecting an issue lies with redirector configuration, first consider if the issue would happen if a faulty modem cable were suspected on a local modem.

Software Modem Cable Limitations

When a redirector is used with a server that does not support COM Port Control, this software modem cable is similar to a hardware modem cable that has only three wires: TD, RD and ground. There is no provision for control/status lines such as CD, DTR and DSR to pass data between the PC and the modem.

Thus, the client PC raising or dropping DTR has no effect on the actual DTR pin on the modem. In addition, baud-rate and framing information cannot be controlled over the TCP/IP connection. If the client PC opens the port at 38400 8-N-1, but the modem pool's hardware port is configured to be 9600 7-E-1, then the physical modem will not communicate using 38400 8-N-1.

None of these limitations exist when the redirector is used with a server that supports COM Port Control. But if COM Port Control is not present in a misbehaving equipment configuration, it is important to understand these limitations and to investigate their impact on the client applications being used.

How the Redirector Fits In

The redirector sits "underneath" the COM port API in Windows. It takes data that is directed to a COM port using this API and sends it over the network. Data from the network is passed back through this API as though it came from a hardware COM port.

Unimodem is the part of the Windows operating system that maintains the list of modem devices which have been installed in the system. It sits "above" the COM port API in Windows.

Using these modem devices it initializes and dials modems by sending data to the COM port API and watching for appropriate responses from this COM port API. When an application uses Unimodem to open a modem device on a local COM port (COM2 for example), it sends/receives data from hardware.

When an application opens a modem device on a redirected COM port, it still sends/received data from hardware, but it is up to the redirector to move the data to the actual hardware elsewhere on the network.

This raises another important point: it is Unimodem that actually interacts with the modem when it is time to initialize and dial. The redirector is simply a conduit for Unimodem, just like a physical modem cable. If dialing fails, it is often because Unimodem is receiving unexpected responses from the modem

The Auto Configure as a Litmus Test

The Auto Configure in Tactical Software redirector products is a very helpful tool to ensure that the redirector is configured for a clear data path to the modem.

If the Auto Configure runs successfully, the chances are high that the redirector itself is configured properly. To continue the analogy, if this test proves the "modem cable" is plugged in properly, then problems from then on are likely to lay elsewhere.

Introduction

Tactical Software redirectors support a public protocol known as The COM Port Control Protocol, specified by IETF RFC 2217. COM Port Control overcomes limitations of networked modem servers that can cause compatibility issues with some PC applications.

Many PC applications can use modem/serial servers that don't support the COM Port Control Protocol. For those applications that need the extra features provided by the protocol, Tactical Software redirectors do include support for it.

For the protocol to benefit the application, the server must also support the protocol.

The Additional Capability of Servers Supporting the COM Port Control Protocol

COM Port Control is an extension of the Telnet protocol, so it will only be available if the Tactical Software redirector is configured to use Telnet.

When the redirector is so configured, it will always request that the connection use COM Port Control. If the server agrees to use COM Port Control, then will it become active on the current connection to the server.

On a connection without COM Port Control, the client application is able to interact with a server only by sending and receiving data. Serial ports on servers have control signals that can be manipulated by the client software (such as DTR), and report status signals that can be monitored by the client software (such as DSR, DCD and RI).

In addition, there are several parameters that control how the server's serial port communicates with the redirector, including baud rate, data length, number of stop bits and parity type. Without COM Port Control, the client software is unable to affect any of these parameters or signals, and the server cannot report the status signals to the client software.

Alternatives to Servers Supporting the COM Port Control Protocol

If a PC application requires special COM port settings, it may still be able to work with a server that does not support the COM Port Control protocol. Often, an effective workaround is to configure some server ports specifically for the use of such an application.

For example, some modems on a server might need to be configured for 1200 E-7-1 in order to work with an alphanumeric paging application; but those modems from then on would likely work only with that one application, given the specialized nature of those settings.

COM Port Control Protocol Features Available in Tactical Software Redirectors

Tactical Software redirectors use the COM Port protocol to provide the following port controls:

• Baud rate (e.g., 9600)
  
• Data Length (e.g., 8 bits)
  
• Parity bit (e.g., none)
  
• Stop bits (e.g., 1 stop bit)
  
• DTR signal (often used to disconnect a call)

Tactical Software redirectors use the COM Port protocol to report the following port conditions:

• DCD (signals that a call succeeded)
  
• DSR (signals that the modem is ready)
  
• RI (signals that the phone is ringing)
  

COM/IP, DialOut/EZ and Serial/IP redirectors are kernel-level device drivers, therefore they can not be specified as exempt applications in most firewall programs, as they are part of the Windows System Process.

The License Manager and TacServe are Windows Services that can be specified when configuring a firewall.

The Tactical Software Installer will modify the Microsoft Windows Firewall settings to allow our products to work correctly. However, incoming TCP connections to Serial/IP or COM/IP still need to be added manually.

Software offered by Tactical Software does not use Java or Apache and does not have the Log4j security vulnerability.

An API for Run-time Reconfiguration

Beginning in version 4.4 of the Serial/IP Redirector, a Component-Object-Model (COM)-based API allows external programs and scripts to change all aspects of the Serial/IP configuration.

Using the ActiveX API, your application can make any Serial/IP configuration change that you could make manually in the Serial/IP Control Panel, including:

• Add and remove Serial/IP virtual COM ports.
• Change the setting for any option on any Serial/IP virtual COM port.
• Change any Serial/IP setting in the global options and proxy server support.

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Technical Overview

The API exports a single top-level object TacticalSoftware.SerialIPRedirector which implements the ITSRedirectorConfiguration interface. This object contains sub-objects which are accessible as properties.

The following VBScript example creates a single Serial/IP virtual COM port and configures it:

Dim SerialIPDim SerialPortSet SerialIP = CreateObject(“TacticalSoftware.SerialIPRedirector”)Set SerialPort = SerialIP.Ports("COM5")

` Set the Address and Port SerialPort.ServerAddress = "10.0.1.29"SerialPort.ServerPort = 7000` Configure for Telnet and Prompt-On-Port-Open AuthenticationSerialPort.TelnetProtocol = TSTelnetSerialPort.UserAuthentication = TSAuth_PromptAtPortOpen` Turn on Connection Restore SerialPort.RestoreFailedConnections = TRUE

When viewing a failed dialout attempt in the Trace Window, a modem's NO CARRIER reply to the ATDT dial string is the most common issue. A NO CARRIER reply back from the modem is a sign that the modem was unable to establish a connection to the remote endpoint.

This can happen if the modem is told to dial a malformed or non-existent number, a telco problem is present, or a modem negotiation issue causes the connection to fail.

A malformed number is when the format of the number being dialed is incorrect. Possible causes include a '9' is being dialed but not needed to acquire an outside line, an area code and/or leading '1' is missing, the dialed number is simply incorrect, or there are characters in the number that the modem can not process.

A telco issue means that the telephone service lines (T1 or POTS) connected to the modem server are not capable out making outbound calls or the lines don't have a long distance carrier.

Both this and the above malformed number condition usually show the NO CARRIER response returned within a second of the dial command.

A modem negotiation problem occurs when the two modems can not agree on the communication protocols to be used. To fully diagnose this type of problem, it may be necessary to see the CONNECT string from a successful connection to that endpoint with a local modem to determine what baud rate, error correction and data compression are required by the destination modem.

Introduction

The Application Compatibility checkbox options in the DialOut/EZ Control Panel can help certain types of modem applications work with modem servers that do not support the COM Port Control protocol.

When COM Port Control is available on the modem server, these options have no effect.

DTR Is Modem Escape

The DTR Is Modem Escape option controls how the DialOut/EZ Redirector responds to the manipulation of the DTR line.

The most common situation with DTR is when the client software drops the line from high to low, which in most cases will cause the modem to return to the AT Command mode. Windows Unimodem uses the DTR line in the course of the hangup sequence.

This sequence is as follows:

• Drop DTR to low.
  
• Wait for an "OK" which signals that the modem is awaiting a command.
  
• Send "ATH" to instruct the modem to hang up. 

Without COM Port Control, the DialOut/EZ Redirector cannot instruct the server to drop the DTR line, leaving Unimodem without a way to initiate this sequence. Fortunately, nearly all modems respond to an escape sequence ("+++" followed by a pause) which performs the same action as dropping the DTR line.

Therefore, when the DTR Is Modem Escape option is enabled and the DTR line drops from high to low, the redirector responds with the following sequence: "+++" is sent to the modem. Data transmission is blocked for one second to enforce the pause after the "+++".

With DTR Is Modem Escape enabled, the DialOut/EZ Redirector is able to emulate the DTR dropping with the escape sequence, allowing Unimodem to successfully perform the hangup sequence.

It is almost always counterproductive to experiment with this setting during a troubleshooting session. The value chosen by the Auto Configure is usually the correct one. There should be good reason to believe that the DTR emulation is causing application compatibility problems before attempting a fix by configuring this option manually.

Assert DCD/DSR After COM Port Open

This option controls how the DialOut/EZ Redirector presents the value of the DCD (Data Carrier Detect) and DSR (Data Set Ready) lines.

Most applications work correctly when DialOut/EZ reports both lines as low. Because many Windows modem devices will not dial properly unless these lines are reported as low, this is the default behavior of DialOut/EZ. However, certain applications will not dial properly when the DCD/DSR lines are always held low.

The dialing sequence should be as follows:

• Dial the number by typing the ATDT command.
  
• Wait for the modem to respond with "CONNECT".
  
• Check that the DCD line is high If the DCD line is low, the application considers the dialing to have failed.
  

Therefore, when the Assert DCD/DSR option is enabled, DialOut/EZ always reports the DCD and DSR lines as high. This enables the application's dialing sequence to complete successfully.

It can be helpful to try changing the value of this option when troubleshooting a DialOut/EZ redirector installation.

For example, if HyperTerminal dials successfully, but another application does not, enabling this option is a useful experiment.

Note: There are applications that simply will not work without COM Port Control. These are beyond the help of the Assert DCD/DSR option, as some applications not only require DCD to be high, but also require that DCD start out as low and then transition to high during the dialing phase.

This Technical Article applies exclusively to the DialOut/EZ Site Edition redirector running under Microsoft Windows Terminal Services or the Citrix MetaFrame Access Suite. Note: On a multi-user computer you can install only DialOut/EZ Site Edition or TacServe Edition. When installing the DialOut/EZ software on a multi-user operating system, the configuration of the client software and the modem server will be slightly different than for single-user operating systems. Any DialOut/EZ COM port, like a real hardware COM port, can be used by only one PC application at a time.

Managing the use of DialOut/EZ COM ports by multiple users is a key issue. In the instructions below, each user gets separate DialOut/EZ COM Ports and modem devices.

1. Run the DialOut/EZ setup program.
   
2. When the Select Ports Window appears, set up the maximum number of DialOut/EZ COM ports that the users will need. Some users may need to have more than one dial-out session active at one time and will need more than one DialOut/EZ COM port.
3. The Windows modem installation wizard will now launch. This wizard assigns a modem driver to each new COM port. When instructed to assign a modem driver to the ports, select all DialOut/EZ COM ports. This insures that all ports will have the same modem driver.
4. Open the DialOut/EZ Control Panel. Assign to each port the IP Address and Port Number of the hunt group on the modem server.
5. Each user will now only use the DialOut/EZ COM ports assigned to them and the modem server will automatically give them the next available modem. If no modem is available, the user will see an error message from the PC application using the COM port.

Using Backup Modem Servers

Tactical Software's redirectors have a failover feature to prevent dial-out failures when a modem server stops responding. This could be due to a hardware failure or when the modem pool reaches its capacity.

The failover feature allows entry of more than one modem server (either as an IP address or DNS name) in a space-separated list in the DialOut/EZ Control Panel.

If DialOut/EZ is unable to make a connection to the first modem server in the list, it will try the second, third, then fourth, until it finds a modem server that accepts a TCP/IP connection or all four are checked.

This feature also works with the DialOut/EZ Auto Configure feature, thus allowing users to see what modem servers are not responding to TCP connection attempts.

If using a second modem server is cost prohibitive, a Windows PC with modems can be made into a backup modem server with our TacServe Modem Pool Server and accessed with any DialOut/EZ client.

Using Backup License Managers

The location of the License Manager under the Licensing button accepts a space-separated list of up to four IP addresses or hostnames. DialOut/EZ will try every License Manager listed until it receives a license or the list is exhausted. 

Example: If the site requires a 64 simultaneous connections, instead of using one 64-port License Manager, use four 16-port License Managers. On the DNS server, configure the entry for the License Manager with four A-records, each pointing to a different License Manager machine. Then configure each DialOut/EZ Site Edition client with the hostname under the Licensing button.

When the DialOut/EZ Site Edition tries to obtain a license it will query the DNS server and obtain all four IP addresses of the License Manager systems. The DialOut/EZ Site Edition client will try each of the four License Manager machines before a licensing failure will occur.

DialOut/EZ Site License keys are used by the DialOut/EZ License Manager and are tied to the IP address of the server machine it runs on.

To move the License Manager to a different server (with a different IP address), begin by using the form Change Site License Server.

When this form is processed by Tactical Software, you will receive an email with two site license keys, to be used as follows.

To provide a transition period with uninterrupted operation, the following procedure allows you to run the License Manager on both old and new servers for up to 60 days.  The order of these steps is important.

Step 1: Prepare for parallel operation

One of the license keys is a temporary key for the old server IP address, with an expiration date 60 days from the date of the email. 

In the DialOut/EZ License Manager on the new server, use the Licensing command to replace the current license key on the old server with this temporary license key.  It will not conflict with the new license key that is installed in the step 2.

Step 2: Installation of new license key

In the DialOut/EZ License Manager on the new server, use the Licensing command to install the other license key, which does not expire.

Please note that if the original license key remains in use, both it and this key will conflict and suspend License Manager operations.  This is why we provide the temporary non-conflicting license key in step 1.

Step 3: Change DialOut/EZ Redirectors to use new license server

For each installation of DialOut/EZ Site Edition Redirector, use the Licensing button to change to the new license server.  You may specify an IP address or a hostname.

All Tactical Software redirectors have features that support unattended installation, which simplify deployment to multiple users.

Products can be installed or removed with a command line, with no user interaction required and an existing configuration can be captured and re-used automatically in additional installs.

The following four articles should be read before using the Unattended Installation features. These notes describe the options available for command line installations, rolling out pre-configured clients, and important things to consider before attempting an unattended install.

• Packaging and Command Line Options shows the command line options and install kit property overrides.
  
  
• Configuration Snapshots describes how to use the Tactical Software Configuration Snapshot Utility to copy the settings from one machine and use this information to install and configure the software on other PCs.
  
  
• Differences Between MSI and EXE Files describes the differences between the two file types and when to use MSI files instead of EXE files.
  
  
• Upgrades of Pre-4.2 Versions describes uninstalling any version made before 4.2. If version 4.2 or above is installed, skip this tech note.
  

Tactical Software redirectors supporting unattended installs have numerous options available to them, in two basic categories, command line options and onstall-kit property overrides.

These options work with both the EXE and MSI files.

The following command line options can be used:

• /q - Quiet installation. No messages are displayed whatsoever. In most cases must be accompanied by property overrides to supply information normally gathered by the installation's GUI. Used for unattended installs.
  
• /qb - "Basic" UI. Shows basic installation progress dialogs, but the user is given no opportunity to configure how the installation is performed. Usually must be accompanied by property overrides.
  
• /x - Remove the product from the system, if installed.

In addition to command line options, the value of installation "properties" can be overridden on the command line using a "name=value" syntax.

For example, to specify an alternate directory for the installation, the PRODUCTDIRECTORY property must be overridden as shown below:

SerialIP4912.exe PRODUCTDIRECTORY="C:\Tactical" LICENSEKEY="AAAA-AAAA-AAAA-AAAA-AAAA"

The following properties are supported:

• USERNAME - Name of the licensed end-user, will be presented in the About Box of the product after installation.
  
• COMPANYNAME - Name of the company, will be presented in the About Box of the product after installation.
  
• LICENSEKEY - License Key to use for this installation. Not used for Site Edition clients. Must be used with the Seat Edition.
  
• LICENSEMGR - Hostname or IP Address of the License Manager. Not used for Seat Edition clients. Must be used with DialOut/EZ Site Edition.
  
• PRODUCTDIRECTORY - Location to install the product files on the target system. This specifies a root directory for the installation with the default root at "C:\Program Files\Tactical Software". The product's files are installed in a subdirectory of the root directory, with the name of the subdirectory not being configurable. Using PRODUCTDIRECTORY="C:\Tactical" for DialOut/EZ, would cause the product files will be installed to "C:\Tactical\DialOutEZ".
  
• ADDLOCAL - Specifies a comma-separated list of features to be installed. No spaces are allowed between features (just the comma). See more information below.
  
• TSINSTALLMODE - Must be set to "NOLOGIN" if the install kit is to be installed while no user is logged in (this is one of the SMS install options). Typically used with /q, and causes the installer to (a) not launch the System Tray, and (b) defer launching the Control Panel until the next user login.
  
• CONFIGSNAPSHOT - Configuration Snapshot file to apply during installation. See Configuration Snapshots for more information.

The property names are case-sensitive, so the above properties must be in all-uppercase when specified on the command line.

Also, the properties are not applicable to the entire product line:

• The License Managers only support the PRODUCTDIRECTORY option.
  
• TacServe supports only the LICENSEKEY and PRODUCTDIRECTORY options.
  
• The Site Edition clients do not support USERNAME and COMPANYNAME options.
  

The ADDLOCAL property allows the end-user to configure which features are to be installed.

For the client products, there is one optional feature: Administrator-Only Mode. By default, the install kits do not install the Administrator-Only Mode.

To install only the product for DialOut/EZ, specify the following:

DialOutEZ4912.exe ADDLOCAL="DialOutEZ" LICENSEKEY="AAAA-AAAA-AAAA-AAAA-AAAA"

To install the product with Administrator-Only Mode, specify the following:

 DialOutEZ4912.exe ADDLOCAL="DialOutEZ,DialOutEZAOM" LICENSEKEY="AAAA-AAAA-AAAA-AAAA-AAAA"

The following enumerates the complete list of feature names that may be specified for ADDLOCAL:

Main Product   Administrator-Only Mode
COMIP            COMIPAOM
DialOutEZ       DialOutEZAOM
SerialIP           SerialIPAOM

Introduction

The Tactical Software Installer supports unattended installs via Configuration Snapshots along with the command line options, to perform the configuration of the redirector based on an existing setup.

A Configuration Snapshot is a .CFG file that contains the information about the configuration of the product, including:

• The list of redirected COM ports (i.e., COM5, COM6, COM10, COM11)
  
• Proxy settings SSL/TLS settings Misc settings Preset.txt file (if present)
  
• IP Address and TCP port number of server
  
• Telnet options
  
• Authentication options
  
• COM port options

The License Key or License Manager settings are not present in a configuration snapshot, and must be specified on the Windows Installer command line as necessary during the installation.

The Configuration Snapshot Utility

A configuration snapshot is created with the Configuration Snapshot Utility provided by Tactical Software. Download it here: Configuration Snapshot Utility

To use the Configuration Snapshot Utility:

1. Create and configure the desired COM ports on one PC.
   
2. Run the Configuration Snapshot utility, which creates a .CFG file.
   
3. The drop-down list contains the list of Tactical Software products currently installed on the machine. Select one of the products then click the "Save" button to save the snapshot to a .CFG file.

If only one Tactical product is installed on the machine, that product is selected automatically.

Once the .CFG file is created, it can be specified on the command line to setup identical configurations during the install.

For example:

SerialIP410.exe /q CONFIGSNAPSHOT="c:\si.cfg" LICENSEKEY="AAAA-AAAA-AAAA-AAAA-AAAA"

DialOutEZSiteEdition410.exe /q CONFIGSNAPSHOT="c:\dz.cfg" LICENSEMGR="10.0.0.81"

The full path of the file must be specified, as relative paths are not supported.

Tactical Software offers its installation programs in MSI and EXE files.

Please contact support@tacticalsoftware.com if you require MSI files

Updating Using EXE Files

EXE files are the preferred method for installation, as they are able to detect an existing version of the software and offer the user the option of uninstalling the existing product.

MSI files do not have this ability and will instruct the user to use the Add/Remove Programs on the Windows Control Panel to remove the existing product first.

In many situations, the EXE files combined with pre-configured command-line options would be preferred, especially if /qb is used. The /qb option eliminates dialogs from the GUI that enable the user to override how the product is installed.

The only problem with using EXE files arises when deploying an unattended installation/upgrade. There is no way to instruct the EXE file to uninstall the existing version without first prompting the user.

Updating using MSI files

To implement an unattended upgrade, the MSI file must be used.

Given this limitation, using the MSI file should only be done if it is a requirement that future installations be completely silent. In a completely silent install, the installer is prevented from notifying the user of critical failure conditions such as a COM port being in use. In this situation, the installation will simply do nothing, and there will be no notification that there was a problem.

The /fvams option tells the Windows Installer to treat the MSI file as an upgrade.

For example, to replace the existing version of DialOut/EZ Site Edition with the version found in the MSI file, use following command line: msiexec /fvams DialOutEZSiteEdition.msi

A silent upgrade command line would be: msiexec /q /fvams DialOutEZSiteEdition.msi

This technique has the following limitations:

• The EXE and MSI packaging cannot be mixed and matched if /fvams will be used at a later date. If the product has been installed using the EXE, and then /fvams is attempted as the mechanism for upgrade, the installation will fail with an error.
  
• The /fvams option cannot be used to perform a first-time installation of the product. This could lead to complications when deploying to a large number of desktops where some of the desktops already have the software but others do not.
  
• The name of the MSI file specified via /fvams must be the same filename that was used to install the product originally. This is why the version number of the product is not included in (and should not be added to) the filename of the MSI file.
  
• The /fvams upgrade cannot be used to change the feature set (such as adding or removing Administrator Only Mode).
  

Version 4.2 is the first version based on the latest Windows Installer technology.

The install kit performs additional steps that detect and uninstall pre-4.2 versions of the product. Once a pre-4.2 version is detected, the uninstall is accomplished by running the uninstall program supplied by the pre-4.2 version.

The difference is that privilege elevation cannot be used when running the uninstall program for the pre-4.2 version. Administrator privileges will therefore be required when upgrading from pre-4.2 releases. This is the same situation that existed prior to version 4.2, when Administrator privileges were required for all install/uninstall operations.