User guide

New and Changed Information
18
Release Notes for Cisco 2500 Series for Cisco IOS Release 12.0 T
78-5563-07 Rev.H0
New and Changed Information
The following sections list the new hardware and software features supported by the Cisco 2500 series
for Release 12.0 T:
New Software Features in Release 12.0(7)T
The following new software enhancements are supported by the Cisco 2500 series for Release 12.0(7)T
and later releases:
One New Feature Set
One new feature set has been created for the Cisco 2500 series in Release 12.0(7)T:
• Distributed Director—c2500-w3-l
Dynamic Multiple Encapsulations for Dial-In over ISDN
The Dynamic Multiple Encapsulations feature allows incoming calls over ISDN to be assigned an
encapsulation type such as Frame Relay, PPP, and X.25 based on calling line identification (CLID) or
DNIS. It also allows various encapsulation types and per-user configurations on the same ISDN
B channel at different times according to the type of incoming call.
The Dynamic Multiple Encapsulations feature allows per-user configuration for each dial-in caller on
any ingress ISDN B channel on which encapsulation can be run independently from other B channels
on the same ISDN link. The caller is identified by CLID (caller ID) or DNIS to ensure that only
incoming calls with authorization and valid user profiles are accepted. When PPP is used, authentication
and profile binding can also be done by PPP name.
In addition, a large set of user profiles can be stored in dialer profiles locally or on a remote AAA server.
(For large scale dial-in, storing user-specific configurations on a remote server becomes necessary for
enhancing expandability and local memory efficiency.) However, whether stored locally or on a remote
AAA server, the user-specific encapsulation and configuration can be applied to individual B channels
dynamically and independently.
Dynamic multiple encapsulation is especially important in Europe where ISDN is relatively inexpensive
and maximum use of all 30 B channels on the same ISDN link is desirable. Further, the feature removes
the need to statically dedicate channels to a particular encapsulation and configuration type, and
improves channel usage.
Low Latency Queueing
The Low Latency Queueing feature brings strict priority queueing to Class-Based Weighted Fair
Queueing (CBWFQ). Strict priority queueing allows delay-sensitive data, such as voice, to be dequeued
and sent first (before packets in other queues are dequeued), giving delay-sensitive data preferential
treatment over other traffic.
Without Low Latency Queueing, CBWFQ provides weighted fair queueing based on defined classes
with no strict priority queue available for real-time traffic. CBWFQ allows you to define traffic classes
and then assign characteristics to that class. For example, you can designate the minimum bandwidth
delivered to the class during congestion.