test tcp

Unanswered Question
May 11th, 2009

Hi ,

I have two sites with 1024k links in UK. The links behaves as if they are rate limitted even though i dont have any rate limitting set on the router. The customer for instance sent a 3meg file from a site locally to the UK site. it went up to about 900k and then while the file is being copied it went down and flacuates between 400k and 600k. Can someone advise what to do ? I tried using test tcp the telnet session times out before I can get any results. i dont see much traffic on my WAN interfaces as well.



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sithellp Mon, 05/11/2009 - 09:04

we did 3 simultaneous sessions with 880k pings to get the link full but while all this is going the traffic decreases


sithellp Mon, 05/11/2009 - 09:09

Am I wrong to think that if I copy 3meg files from 3 different sources and a 800 size ping the link should remain full at least until one of these is finished ?

Paolo Bevilacqua Mon, 05/11/2009 - 09:14

Three copies may or may not fill a link. 3 meg files are also too small for testing.

Pings, irrespective of size, are pretty much indifferent.

Again, you need to check "show interface".

sithellp Mon, 05/11/2009 - 12:16

I saw the decrease in traffic on the link from the " sh interfaces"

I need to be able to see the results of the ttcp as I know It will at least give me somthing. I could only see very little traffic than what I saw when i was testing ttcp in my lab. Any suggestions?

Paolo Bevilacqua Mon, 05/11/2009 - 12:23

The reason I was asking for show interface, its because it also show errors and queue statistics, these are indication of congestion experienced.

Without supporting output, your question remains too vague and cannot be answered.

sithellp Mon, 05/11/2009 - 12:28

apologies didnt understand. I dont have "sh int" from the test I did but I will send you the sh int from the sites i ahve problems on:

#sh int s0/0/0:0

Serial0/0/0:0 is up, line protocol is up

Hardware is GT96K Serial


Internet address is

MTU 1500 bytes, BW 1024 Kbit, DLY 20000 usec,

reliability 255/255, txload 27/255, rxload 5/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

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

Last clearing of "show interface" counters 04:19:32

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

Queueing strategy: Class-based queueing

Output queue: 2/1000/64/0 (size/max total/threshold/drops)

Conversations 1/27/256 (active/max active/max total)

Reserved Conversations 4/4 (allocated/max allocated)

Available Bandwidth 12 kilobits/sec

30 second input rate 22000 bits/sec, 32 packets/sec

30 second output rate 109000 bits/sec, 44 packets/sec

528526 packets input, 82650255 bytes, 0 no buffer

Received 1557 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

884392 packets output, 289925088 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

Timeslot(s) Used:1-16, SCC: 0, Transmitter delay is 0 flags


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