User guide

25
Release Notes for Cisco 2500 Series for Cisco IOS Release 12.0 T
78-5563-07 Rev.H0
New and Changed Information
X.25 Remote Failure Detection
Static routes are used over a packet-switched data network in order to reduce volume-based costs of the
network. Until now, if two routers were connected via multiple X.25 links (a primary and a secondary),
a router could not detect failure of the primary link. If a failure occurred, the data was not transferred
to the second link because X.25 was unable to determine whether remote links were up or down.
Therefore X.25 could not use an alternate connection to a destination.
The X.25 Remote Failure Detection feature is important for X.25 users because now, after a primary
link failure, the router can establish a secondary link and continue sending data. This feature is a way
for the router to detect a call failure and to use a secondary route to send subsequent packets to the
remote destination, at the same time as making periodic attempts to reconnect to its primary link.
New Software Features in Release 12.0(4)T
The following new software enhancements are supported by the Cisco 2500 series in Release 12.0(4)T
and later releases.
One New Feature Set
One new feature set has been created for the Cisco 2500 series in Release 12.0(4)T:
• IP/H.323—c2500-ix-l
Dynamic Multiple Encapsulations for Dial-in over ISDN
The Dynamic Multiple Encapsulations feature allows incoming calls over Integrated Services Digital
Network (ISDN) to be assigned an encapsulation type such as Point-to-Point Protocol (PPP), X.25, and
ISDN Link Access Procedure, Balanced-Terminal Adapter (LAPB-TA) based on calling line
identification (CLID) or Dialed Number Identification Service (DNIS). It also allows various
encapsulation types as well as 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 or DNIS to make sure that only incoming calls
with authorization and valid user profiles are accepted. If the protocol is PPP, authentication and profile
binding can also be done by PPP name.
Dynamic multiple encapsulations are especially important in Europe where ISDN is relatively
inexpensive, and it is desirable to allow maximum use of all B channels on the same ISDN link,
especially for large scale dial-in. Further, the feature removes the need to statically dedicate channels
to a particular encapsulation and configuration type, and improves channel usage.
Although the Dynamic Multiple Encapsulations feature enhances large scale dial-in functionality, the
feature also works well in smaller scale dial-in situations and for modem calls.
New Software Features in Release 12.0(3)T
The following new software enhancements are supported by the Cisco 2500 series in Release 12.0(3)T
and later releases.