Cisco IOS Wide-Area Networking Configuration Guide - Free Books

Configuring X.25 and LAPBConfiguring an X.25 Datagram TransportCommandRouter(config-if)# x25 map protocol address [protocol2 address2[...[protocol9 address9]]] x121-address [option]PurposeMaps one or more host protocol addresses to theX.121 address of the host.For example, if you are encapsulating IP over a given X.25 interface, you must define an IP address forthe interface and, for each of the desired destination hosts, map the IP address of the host to its X.121address.NoteYou can map an X.121 address to as many as nine protocol addresses, but each protocol can be mappedonly once in the command line.An individual host map can use keywords to specify the following protocols:• apollo—Apollo Domain• appletalk—AppleTalk• bridge—Bridging• clns—OSI Connectionless Network Service• compressedtcp—TCP/IP header compression• decnet—DECnet• ip—IP• ipx—Novell IPX• pad—Packet assembler/disassembler• qllc—IBM QLLC• vines—Banyan VINES• xns—XNSEach mapped protocol, except bridging and CLNS, takes a datagram address. All bridged datagrams areeither broadcast to all bridging destinations or sent to the X.121 address of a specific destination host,and CLNS uses the mapped X.121 address as the subnetwork point of attachment (SNPA), which isreferenced by a clns neighbor command. The configured datagram protocols and their relevantaddresses are mapped to the X.121 address of the destination host. All protocols that are supported forRFC 1356 operation can be specified in a single map. (Bridging and QLLC are not supported for RFC1356 encapsulation.) If IP and TCP/IP header compression are both specified, the same IP address mustbe given for both protocols.When setting up the address map, you can include options such as enabling broadcasts, specifying thenumber of VCs allowed and defining various user facility settings.NoteMultiprotocol maps, especially those configured to carry broadcast traffic, can result in significantlylarger traffic loads, requiring a larger hold queue, larger window sizes, or multiple VCs.For specific information about how to establish a protocol to run over X.25, refer to the appropriateprotocol chapters in the Cisco IOS IP Configuration Guide, Cisco IOS AppleTalk and Novell IPXConfiguration Guide, and Cisco IOS Apollo Domain, Banyan VINES, DECnet, ISO CLNS, and XNSConfiguration Guide.23