Chapter 12: AI2524 X.25 Configuration Steps
August 1997 Page 12-23
2524UM
Configure Additional X.25 Datagram Transport Features
The Cisco IOS software allows you to configure additional X.25 dat-
agram transport features, including various user facilities defined for
X.25 call setup.
This section describes the X.25 datagram transport features you can
configure by using the options in the

x25 map

or x25 pvc en-
capsulation command (or by setting an interface default). Th
tasks you perform depend upon your needs, the structure of your net-
work, and the requirements of the service provider.
To configure the optional parameters, user facilities, and special fea-
tures, perform one or more of these tasks:
zConfigure X.25 Payload Compression
zConfigure the Encapsulation Virtual Circuit Idle Time
zIncrease the Number of Virtual Circuits Allowed
zConfigure the Ignore Destination Time
zEstablish the Packet Acknowledgment Policy
zConfigure X.25 User Facil ities
zDefine the Virtual Circuit Packet Hold Queue Size
zRestrict Map Usage

Configure X.25 Payload Compression

For increased efficiency on relatively slow networks, the Cisco IOS
software supports X.25 payload compression of outgoing encapsula-
tion traffic.
Several restrictions apply to X.25 payload compression:
zThe compressed virtual circuit must co nne ct two Cisco routers,
because X.25 payload compression is not standardized.
The data packets conform to the X.25 prot ocol rules, so a com-
pressed virtual circuit can be switched through standard X.25
equipment. However, only Cisco route rs can compress and de-
compress the data.
zOnly datagram traffic can be compressed, although all the encap-
sulation methods supported by Cisco routers are available. For ex-
ample, an IETF multiprotocol virtual circuit can be compressed.
SVCs cannot be translated between compressed and uncom
pressed data, nor can PAD data be compressed.