Solved

VPLS Circut Slow Speed - TCP Window Size

Posted on 2013-06-12
2
840 Views
Last Modified: 2013-07-22
Hey Guys,

We just got a VPLS circuit installed between two office locations and I’m running some initial tests on the connection. We are committed to 10mbps at each of the endpoints, however when running ipref tests looks as though we are getting 500-700kbs. I spoke to the provider who seems to be blaming it on our Windows OS Operating System TCP Window size. After changing the windows size in the ipref test this increases the bandwidth speed up to about 5-7mbps.

So because of these tests the slow speed looks like its isolated to the TCP window size. The question is why is the bandwidth transfer from our other providers absolutely fine, however with this one they are telling me to change my TCP window size across the whole network ???
0
Comment
Question by:supportemea
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 57

Assisted Solution

by:giltjr
giltjr earned 250 total points
ID: 39243224
It not clear from your post, but are the " .... bandwidth transfer from our other providers ...." going over the same physical link?

If not, what is the latency on the other link?

To fully utilize the available bandwidth of a link you have to send enough data to keep the pipe full while you wait for an ACK to send more data.  In TCP this is the "window size".  The window size is determined by the speed of the link and the latency.

If you are comparing two different links, you have to know the latency on both and the bandwidth is on both.  If you have two links with equal bandwidth, but one has twice the latency than the other one, the one with the higher latency will get lower through-put.
0
 
LVL 32

Accepted Solution

by:
harbor235 earned 250 total points
ID: 39254167
5-7 Mbps using TCP as transport is not out of line for a 10Mbps connection, remember there is overhead when using TCP.

Try using udp for the test, it should provide better numbers.


iperf -su  (server side)
iperf -c <server_ip> -u -i 1 -b 10m  (client side)

for a longer test specify  (-t 300) in the command line for a 5 minute test

iperf -c <server_ip> -u -i 1 -t 300 -b 10m  (client side)

harbor235 ;}
0

Featured Post

Simple, centralized multimedia control

Watch and learn to see how ATEN provided an easy and effective way for three jointly-owned pubs to control the 60 televisions located across their three venues utilizing the ATEN Control System, Modular Matrix Switch and HDBaseT extenders.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: rfc1180
The Maximum Segment size (MSS) is an important consideration when troubleshooting connectivity via the Internet/Intranet. As the packets are routed via the Internet/Intranet, the packets must traverse through multiple routers in the path between two…
Configuring network clients can be a chore, especially if there are a large number of them or a lot of itinerant users.  DHCP dynamically manages this process, much to the relief of users and administrators alike!
In this video we outline the Physical Segments view of NetCrunch network monitor. By following this brief how-to video, you will be able to learn how NetCrunch visualizes your network, how granular is the information collected, as well as where to f…
This tutorial will teach you the special effect of super speed similar to the fictional character Wally West aka "The Flash" After Shake : http://www.videocopilot.net/presets/after_shake/ All lightning effects with instructions : http://www.mediaf…

617 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question