Specifications

5-12
Cisco AS5x00 Case Study for Basic IP Modem Services
11/24/1999
Section 5 Configuring PPP and Authentication
Inspecting Active Call States
6.2 Fast Switching and Route Caching Statistics
Inspect fast-switching and route-caching performance statistics for the call. Incoming asynchronous
calls can be fast switched. However, some features disable fast switching.

Inspect the queueing characteristics of the asynchronous interface. Notice that the queueing
strategy is first-in-first-out (fifo).
5800-NAS#show interface async 1/2/02
Async1/2/02 is up, line protocol is up
modem=1/2/02, vdev_state(0x00000000)=CSM_OC_STATE, bchan_num=(T1 1/0/0:4:6)
vdev_status(0x00000001): VDEV_STATUS_ACTIVE_CALL.
Hardware is Async Serial
Interface is unnumbered. Using address of FastEthernet0/1/0 (172.22.66.23)
MTU 1500 bytes, BW 9 Kbit, DLY 100000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, loopback not set, keepalive not set
DTR is pulsed for 5 seconds on reset
LCP Open
Open: IPCP
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/10, 0 drops; input queue 1/10, 0 drops
5 minute input rate 0 bits/sec, 1 packets/sec
5 minute output rate 0 bits/sec, 1 packets/sec
1683 packets input, 112764 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
1 input errors, 1 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
1626 packets output, 108235 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions

Inspect the IP settings of the interface. Notice that IP fast switching is disabled, because TCP/IP
header compression is enabled. Turn off TCP/IP header compress to enable fast switching.
Enter the
no ip tcp header-compression
command on the asynchronous interface.
5800-NAS#show ip int async 1/2/02
Async1/2/02 is up, line protocol is up
Interface is unnumbered. Using address of FastEthernet0/1/0 (172.22.66.23)
Broadcast address is 255.255.255.255
Peer address is 172.22.90.2
MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is enabled
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Security level is default
Split horizon is enabled
ICMP redirects are always sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is disabled
IP fast switching on the same interface is disabled
IP multicast fast switching is enabled
Router Discovery is disabled
IP output packet accounting is disabled
IP access violation accounting is disabled
TCP/IP header compression is enabled and compressing
RTP/IP header compression is disabled