Cisco Cisco IOS Software Release 12.2(27)SBC

© 2006 Cisco Systems, Inc. All rights reserved.

The TCP Explicit Congestion Notification (ECN) feature provides a method for an intermediate router 
to notify the end hosts of impending network congestion. It also provides enhanced support for TCP 
sessions associated with applications that are sensitive to delay or packet loss including Telnet, web 
browsing, and transfer of audio and video data. The benefit of this feature is the reduction of delay and 
packet loss in data transmissions.

Configuration information is included in the “Configuring TCP” module of the Cisco IOS IP Application 
Services Configuration Guide, Release 12.4T,

at the following URL:

The following sections provide information about this feature:

TCP Explicit Congestion Notification

Configuring TCP Performance Parameters

Verifying TCP Performance Parameters

Verifying the Configuration of TCP ECN: Example

For a complete list of features included in the “Configuring TCP” module, see the Feature Information 
Table located toward the end of the module.

Command reference information is included in the Cisco IOS IP Application Services Command 
Reference

Release 12.2SB, at the following URL:

The following commands are new or modified for this feature: