346
Verifying the configuration
The virtual circuit configured in this example is an SVC. The routers establish it only when they need
to communicate.
# Ping Router B from Router A.
[RouterA-Serial2/0] ping 202.38.60.2
PING 202.38.60.2: 56 data bytes, press CTRL_C to break
Reply from 202.38.60.2: bytes=56 Sequence=1 ttl=255 time=33 ms
Reply from 202.38.60.2: bytes=56 Sequence=2 ttl=255 time=27 ms
Reply from 202.38.60.2: bytes=56 Sequence=3 ttl=255 time=26 ms
Reply from 202.38.60.2: bytes=56 Sequence=4 ttl=255 time=26 ms
Reply from 202.38.60.2: bytes=56 Sequence=5 ttl=255 time=26 ms
--- 202.38.60.2 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 26/27/33 ms
The output shows that the SVC has been established between the two routers.
# Display the X.25 address mapping table on Router A.
[RouterA-Serial2/0] display x25 map
Interface: Serial2/0(protocol status is UP)
ip 202.38.60.2 X.121 address:20112452
Map-type: SVC_MAP VC-number: 1
Facility:
# Display X.25 virtual circuit information on Router A.
[RouterA-Serial2/0] display x25 vc
Interface: Serial2/0
SVC 1024
State: P4(transmit)
Map: ip 202.38.60.2 to 20112452
Window size: input 5 output 5
Packet Size: input 1024 output 1024
Local PS: 5 Local PR: 5 Remote PS: 4 Remote PR: 5
Local Busy: FALSE Reset times: 0
Input/Output:
DATA 5/5 INTERRUPT 0/0
RR 0/0 RNR 0/0 REJ 0/0
Bytes 420/420
Send Queue(Current/Max): 0/200
Direct connection of two routers connecting through serial
interfaces (two address mappings)
Network requirements
As shown in Figure 137, two routers are connected directly; IP packets can be transmitted between
serial interfaces over the X.25 link layer protocol. Two IP to X.121 mappings are available on Router
A.