- Terminal Services Overview
- Configuring Terminal Operating Characteristics for Dial-In Sessions
- Configuring Dial-In Terminal Services
- Cisco IOS Software Feature Removal
- Configuring AppleTalk Remote Access
- Configuring the Cisco PAD Facility for X.25 Connections
- PAD Subaddress Formatting Option
- Configuring Protocol Translation and Virtual Asynchronous Devices
- Authorization for Protocol Translation
- End-of-Record Function for DCNs
- Protocol Translation Ruleset
- Regular Expressions
- X.3 PAD Parameters
- Contents
- Prerequisites for End-of-Record Function for DCNs
- Restrictions for End-of-Record Function for DCNs
- Information About End-of-Record Function for DCNs
- How to Configure End-of-Record Function for DCNs
- Configuration Examples for End-of-Record Function for DCNs
- Additional References
- Command Reference
End-of-Record Function for DCNs
The Cisco Protocol Translator is designed to support Telnet-like applications that are stream-based, with no recognition or accommodation for logical records. For record-oriented applications, problems can occur because the record boundaries in X.25 data are lost when translation to TCP occurs. The End-of-Record Function for Data Communications Networks (DCNs) feature provides for the configuration of an End of Record (EOR) marker which allows the X.25 logical boundaries to be marked when translated to TCP. The benefit of this feature is that it allows the preservation of logical boundaries when translating X.25 data to TCP, enabling X.25-based networking solutions to adapt to and benefit from TCP/IP technologies.
Feature History for the End-of-Record Function for DCNs Feature
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Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Contents
Prerequisites for End-of-Record Function for DCNs
X.25 must be configured. For more information on configuring X.25, see the “Configuring X.25 and LAPB” chapter in the Cisco IOS Wide-Area Networking Configuration Guide.
Restrictions for End-of-Record Function for DCNs
This feature is supported only for X25-to-TCP and TCP-to-X.25 protocol translation sessions.
This feature is not supported for any other types of protocol translation sessions.
Information About End-of-Record Function for DCNs
To configure the End-of-Record Function for DCNs feature, you must understand the following concepts:
Data Types
X.25 data is inherently record-oriented. The X.25 protocol defines a bit in the packet called the More-bit (M-bit), which indicates whether the packet should be considered to terminate a logical record.
TCP data is inherently stream-oriented. The TCP protocol attaches no significance to TCP segment stream boundaries, and the boundaries may change if the data is re-sent.
The EOR Marker
Logical record boundaries indicated by the combination of the X.25 packet boundaries and the M-bit are not preserved when translation to TCP occurs. The End-of-Record Function for DCNs feature allows the X.25 logical record boundaries to be marked by inserting a configurable string into the TCP stream at each X.25 record boundary. Translation of X.25 packets without the M-bit will invoke the insertion of the EOR marker.
Benefits of End-of-Record Function for DCNs
The benefit of the End-of-Record Function for DCNs feature is that it allows the preservation of logical boundaries when translating X.25 data to TCP, enabling X.25-based networking solutions to adapt to and benefit from TCP/IP technologies.
How to Configure End-of-Record Function for DCNs
This section contains the following procedures:
- Configuring the End-of-Record Function for a TCP-to-X.25 Protocol Translation Session
- Configuring the End-of-Record Function for an X.25-to-TCP Protocol Translation Session
- Monitoring and Maintaining the End-of-Record Function for DCNs
Configuring the End-of-Record Function for a TCP-to-X.25 Protocol Translation Session
Perform this task to enable the End-of-Record Function for DCNs feature for a TCP-to-X.25 protocol translation session.
SUMMARY STEPS
3.
translate tcp incoming-address [ incoming-options ] x25 outgoing-address [ outgoing-options ] [ global-options ] eor marker [ insert ]
DETAILED STEPS
Configuring the End-of-Record Function for an X.25-to-TCP Protocol Translation Session
Perform this task to enable the End-of-Record Function for DCNs feature for an X.25-to-TCP protocol translation session.
SUMMARY STEPS
3. translate x25 incoming-address [ incoming-options [ pvc number [ pvc-options ]]] tcp outgoing-address [ outgoing-options ] [ global-options ] eor marker [ insert ]
DETAILED STEPS
Troubleshooting Tips
In the event that the End-of-Record Function for DCNs feature is not operating correctly, use the following debug commands in privileged EXEC mode to determine the source of the problem:
Refer to the Cisco IOS Debug Command Reference publication for information about the debug translate, debug x25 all, and debug pad commands.
Monitoring and Maintaining the End-of-Record Function for DCNs
This task results in the display of information about any protocol translation information configured with the translate command.
SUMMARY STEPS
DETAILED STEPS
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Displays information about translation sessions that have been configured. |
Configuration Examples for End-of-Record Function for DCNs
This section contains the following configuration example:
- Configuring the End-of-Record Function for DCNs for a TCP-to-X.25 Protocol Translation Session Example
- Configuring the End-of-Record Function for DCNs for an X.25-to-TCP Protocol Translation Session Example
Configuring the End-of-Record Function for DCNs for a TCP-to-X.25 Protocol Translation Session Example
The following example configures a TCP-to-X.25 protocol translation session to insert an EOR marker in a TCP packet after each received X.25 packet that does not contain the M-bit set. The EOR marker in this example consists of nonprintable characters and is entered in hexadecimal format.
Configuring the End-of-Record Function for DCNs for an X.25-to-TCP Protocol Translation Session Example
The following example configures an X.25-to-TCP protocol translation session to insert an EOR marker in a TCP packet after each received X.25 packet that does not contain the M-bit set. The EOR marker in this example consists of printable characters.
translate x25 12345678 pvc 3 tcp 10.60.155.63 eor AAA insert
Additional References
The following sections provide additional information related to the End-of-Record Function for DCNs feature.
Related Documents
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Additional information about configuring protocol translation |
“ Configuring Protocol Translation and Virtual Asynchronous Devices |
Additional protocol translation commands: complete command syntax, command mode, defaults, usage guidelines and examples |
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Standards
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MIBs
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To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
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Technical Assistance
Command Reference
The following commands are introduced or modified in the feature or features documented in this module. For information about these commands, see the Cisco IOS Terminal Services Command Reference at http://www.cisco.com/en/US/docs/ios/termserv/command/reference/tsv_book.html. For information about all Cisco IOS commands, go to the Command Lookup Tool at http://tools.cisco.com/Support/CLILookup or to the Cisco IOS Master Commands List.
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