I have 2 3825 w/T3 network module cards on each end of a point to point T3. Ive gone back and forth with our provider (they've tested intrusively, etc)& and Cisco tac. Tac looked at the configuration of the router and said it was fine. However it takes me 30min to download a 140mb file across this link. Does anyone have any suggestions? I checked the clocking, framing, and bandwidth settings on the serial int. Please let me know where i can start.
Have you tried multiple endpoint pairs?
What method are you using to transfer the file(s)?
It is frequently the case where the protocol overhead (i.e., TCP ACKs) reduces the throughput.
To really test out the circuit, you need several endpoint pairs (or multiple sessions on the host(s), up to the capacity of the host(s),) to fill big pipes.
You may be able to use some other testing applications, like QCheck (free, www.ixia.com) to help pump the bandwidth up.
Are you sending the file from one server to another server. I am trying to understand the complete path. When you do a trace route, what are the results?
What are your response times when you go from router to router with 16000 byte pings.
Is the carrier testing to the router or are they testing to the smart jack. I would have them dispatch. I have had problems where the coax used in extended wiring was the problem. How long is the extended demarc? Can you move the routers to the demarc for testing?
What routing protocol are you using?
What card are using?
What IOS version?
I attached a copy of the config of the router. Dont focus to much on the routes. I have them in place and verified that they are working properly. The provider is testing as we speak....the length to the demarc could possibly be an issue but i doubt it is...i will move the routers later on. the card is the NM T3/E3...IOS is 12.3 both routers use Internet Protocol Routing or whatever is default. No OSPF, EIGRP, IGRP, or RIP is enabled on either of the routers.
I've used standard windows transfers to move files. It takes me 20 min to move a 140MB file. I also used solarwinds to test the line and compare the output to the counters on the serial int. The Cisco TAC guys looked at this remotely and said the router looked fine. I attached a copy of the config in another msg. The routes are okay...i just altered them.
as already posted you might just measure the throughput of your TCP/IP protocol stack of the two file transfer machines. What is your CPU load on the Windows boxes when doing the file trasfer?
Also please note: TCP throughput is roughly (window size)/(round trip delay). So with a round trip delay of 100 ms and a window size of 16 kBytes you get a maximum of 1.2 MBit/s, which would be about what you got.
Are you sure it is the 3800 limiting your speed?
Hope this helps
I am guessing you are using a TCP based file transfer to test this link and that you are probably fighting latency issues.
How long (miles) are the circuits? Over 600 miles?
When the circuit utilization is low and you ping from one WAN interface to another what is the round trip time? Is it over 25ms?
At about 25ms round trip time, TCP file transfers will provide a max throughput of 19-20Mbps. As the round trip time increases the throughput decreases when using TCP.
To test throughput of high bandwidth WAN circuits it is often necessary to use UDP or HS-TCP.
Here is a document from the univercd that might help.
Please let me know what you find.
I would double check my config on the controller? Are you sure the clock is line. What is the framing etc...
By the way, I am down in DE! Used to work in Conshy.
Thomuff....At this point no i didnt get the issue fixed. Ive tried everything on the board to no avail. and had a couple of CCIE guys take a look at both routers to verify that the config was right. I have the provider coming out to look at this issue next.
What is the physical length of the circuit(s) and round trip time with a 64 byte ping?
Could also be that the circuit needs to be groomed.
As several others have mentioned here there's probably nothing wrong with the Circuit. CIFS/SMB filecopys are notoriously slow because of there chatty nature. You will very rarely if ever max out a WAN connection using CIFS.
Try iperf on both servers and bring up 4 or 5 connections. You will probably max out your bandwidth that way.