A puzzle for the Teleworker

[RGAIT]

Pardon me if it seems like this question is in the wrong forum, I am puzzled by a problem and need some outside of the box advice.I'm running a remote site with a SRW 208p Linksys Cisco 2gig switch with 6 VoIP phones (Mitel 5312) and 6 PCs thru a Sonicwall Firewall across a WiMax 3meg connection. My connectivty on the WiMax is great and I rarely even begin to use up the bandwidth.My IP phones consistently lose connectivity and drop calls, reboot themselves etc. My WiMax carrier tests clean and we have matched settings on the firewall. When I test the Teleworker connection with TNA I get significant packet loss when it tests 2048 blocks (the 512 and 1024 blks are usually OK) and when I load test it will show Failure at about once every minute.Telecom Vendor,WiMax provider and IT are stumped for something new to try. I have another IP phone from another location ( my home actually) that goes to the Teleworker with no problems I run that on a wireless connection to my cable broadband).Interestingly enough, the 6 phone arrangement went into operation in May and until 3 weeks ago ran quite nicely. Then it started to get flaky and progressed to where its becoming unusable. Ilm looking for ideas/pathways to follow to define the cause of this. Any ideas please? many thanks

 

[jonmyk]

What are the logs showing on the TW? Are you using compression? Did you do any recent firmware upgrades to the equipment (Firewall, Switch)? Can you try a different port on the Sonicwall?



"The only problem with common sense is that it's not that common

 

[aelmore]

Look into fragmented packet handling on the SonicWall and MTU settings of WiMax and SonicWall.

 

[cknipe]

One thing that comes to mind with me is that I used to have wimax/4g modem and I found them less reliable than the older 3g aircards. You might want to find some kind of application that you can place at the remote site that can continually poll the server site and watch for any dropped packets/pings. TCP will always eventually make it there over that connection but the RTP traffic is going to be much more picky and less forgiving. This is kind of out in left field but, Not to mention if you do some homework into wireless networks, net neutrality does not apply to them, only wired ISP connections. So there is no telling if any of that traffic could be throttled, policed, etc being that the provider that you are receiving the service from probably also sells phone service.

another thing you might want to try to rule out the sonicwall vs the ISP is to plug the phone directly into the connection that the ISP is handing you, then configure the phone to use those IP settings for a few hours. Then see if you experience the same issues.

Last, I would always run into issues with remote phones at remote sites when the users at the remote site were connected to a domain controller back at the server site. Sometimes those AD computers can be pretty chatty across the link taking up much of the bandwidth...the solution in that case was to put a DC at the remote site to cut down on the wan chatter....It seems in this instance it had a lot to do with exchange users.

Hope this gets you on the right path.

 

[RDECIT]

In the configuration of your teleworker, what mode are you running it in. Do you have a secondary network card with a WAN address on it presented directed to the internet or are you trying to route packets via the SonicWall.

We tried the routing method, it is just a nightmare. In the end we gave the TW box a separate NIC for the WAN address and plugged it into the router in front of the SonicWall, all problems go away. This is the way Mitel also recommended we did it.