High overrun on hssi interface.

[abhay0212]

Observing high overrun on hssi interface. Need to know if any one have idea why.

[paolo bevilacqua]

What router is thay, what is the output interface, what features are enabled is cef enabled ?

Also post the complete show interface.

[abhay0212]

Router is 3640. Its a bridge interface so lets skip cef. Here is the show interface output.

Hssi2/0 is up, line protocol is up

Hardware is M1T-HSSI-B

MTU 4470 bytes, BW 45000 Kbit, DLY 200 usec,

reliability 255/255, txload 1/255, rxload 6/255

Encapsulation HDLC, crc 16, loopback not set

Keepalive set (10 sec)

Restart-Delay is 0 secs

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters 05:13:27

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

30 second input rate 1208000 bits/sec, 194 packets/sec

30 second output rate 177000 bits/sec, 160 packets/sec

2414032 packets input, 2115674222 bytes, 0 no buffer

Received 218401 broadcasts, 0 runts, 0 giants, 0 throttles

0 parity

8867 input errors, 0 CRC, 0 frame, 8866 overrun, 0 ignored, 1 abort

[paolo bevilacqua]

Hi, on a slow platform like 3640 you have like 0.3% total overruns, it should not be a problem.

Also converting to regular routing should help.

[abhay0212]

Hi,

Any cisco docs on this, which says that the overrun on 3640 with hssi interface is common.

This would help me very much.

[paolo bevilacqua]

Not really, on the other hand is understood that the 3640 is not adequate to deal with the traffic bursts typically associated with hssi and bridging.