From: balaji.balakrishnan (balaji.balakrishnan@swift.com)
Date: Tue Mar 18 2003 - 18:03:44 GMT-3
Thanx for your reply. This is what I found:
The meaning of the line "output buffers swapped out" is explained below:-
"output buffers swapped out" is the number of times the router had to move
buffers from the SRAM (packet memory) to the DRAM (main memory).
The reason that it moves buffers from the SRAM (packet memory) to the DRAM
(main memory)" is when the output queue buffer becomes full. When the output
queue buffer becomes full, the buffers are swapped from SRAM to DRAM to
prevent packets from being dropped. This normlly happens when the output is
congested.
Therefore, the number of "output buffers swapped out" is the total number of
packets stored in DRAM. If the number is high, it could mean that the
traffic is "bursty".If the number of "output buffers swapped out" is high,
it could mean that the line is congested, and may need to be upgraded.
Rgds,
Bala.
Denise Donohue wrote:
> I really like the book Inside Cisco IOS Software, from Cisco Press. I'd
> suggest doing a "show buffers" and see if you have a bunch of created and
> trims in a buffer pool.
>
> -- Denise
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> balaji.balakrishnan
> Sent: Monday, March 17, 2003 12:35 PM
> To: ccielab@groupstudy.com
> Subject: what is mean by "output buffers swapped out" ?
>
> Hi Group,
>
> We had an application (SAP) timeout problem and during that time , I saw
> that the router serila interface output buffer swap
> counter
> was keep incrementing. Do anyone know what is the meaning of that and is
> that anyway related to the performance problem ??
> Also, please post if you know any good link detailing this problem.
>
> Serial4/1/0 is up, line protocol is up
> Hardware is cyBus Serial
> Description: Serial-PPP connection to Serial1/1/7 of GBEAR1
> Internet address is x.x.x.x
> MTU 1500 bytes, BW 256 Kbit, DLY 20000 usec,
> reliability 255/255, txload 43/255, rxload 20/255
> Encapsulation PPP, crc 16, loopback not set
> Keepalive set (6 sec)
> LCP Open
> Open: IPCP
> Last input 00:00:00, output 00:00:00, output hang never
> Last clearing of "show interface" counters 01:54:25
> Queueing strategy: fifo
> Output queue 0/40, 0 drops; input queue 0/75, 0 drops
> 5 minute input rate 21000 bits/sec, 4 packets/sec
> 5 minute output rate 44000 bits/sec, 4 packets/sec
> 64566 packets input, 26162283 bytes, 0 no buffer
> Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
> 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
> 67105 packets output, 46788306 bytes, 0 underruns
> 0 output errors, 0 collisions, 0 interface resets
> 0 output buffer failures, 1211 output buffers swapped out
> 0 carrier transitions
>
> Thanks,
> Bala.
This archive was generated by hypermail 2.1.4 : Sat Apr 05 2003 - 08:51:41 GMT-3