Polycom SoundStation IP 6000 / NEC SV8500 / Calls dropping 1

[bsuggs]

I have an SV8500 in the home office, and a pair of Polycom IP6000s in 2 remote offices with full VOIP solutions (UG50/SR-MGC). Licensing is good. Polycoms in the home office are all analog.

I'm making calls OK with my Polycom IP6000s, but the calls are dropping. Generally, they'll drop hourly, but I've seen them drop quicker. I do not see a distinct pattern. I never lose network connectivity. Pings are stable. AT&T says the IPFlex circuit is good. We have differing AT&T WAN circuits for voice in both offices (MPLS and Switched Ethernet-Network on Demand). Dell says the switch/port configs are good.

My NEC DT700 desk phones do not have the problem. They register to a different SIP server address.

As I wait to hear from NEC, and Polycom says they need a "Polycom Certified" NEC tech on the other end, I'm not a very popular Sys Admin right now.

Any heroes out there able to save this guy some headache and heartache?

Thanks for any feedback,
Bill

 

[belevedere]

Try eliminating the polycom from the equation. Since it is analog, connect a regular 2500 SLT set there and test it.

 

[bsuggs]

Not sure what you mean. It's not an analog polycom. It's a Soundstation IP 6000. Fully IP, for full VOIP. They pull an IP address via DHCP, although I have manual IPs configured in one of the offices.

I'll have to run that 2500 SLT Set by my phone guys. I'm not familiar with it, and Google thinks it's a Dodge Ram.

I'm testing further to be sure the NEC DT700 desk phones are good. I mentioned they do not have a problem in my opening post, but we haven't fully tested. There haven't been reports, which says a great deal, but doesn't rule out more thorough testing. We've had the NEC desk phones in place for over a year. The Polycoms are fairly new to us - about 6 months. I believe no one reported dropped calls until recently, when they had a day-long conference. That's when we started testing.

My work-around is an older, analog, wireless Polycom. These are completely off of the SV8500. They're connected to a true analog copper line.

Thanks for your reply.

Bill

 

[belevedere]

Sorry, I misread your set up. Since it's all IP you may need to set up a wireshark trace on the polycom side to see why it's dropping.
When the call drops do they hear/see anything? Clicking, static, dial tone? You might also check to see if you have an IP address conflict. You could also set up the polycom with a static address to eliminate that possibility.

 

[bsuggs]

Thanks. I'll bet it turns into a Wireshark trace. I'm told there's nothing but dead air when the call drops. I'm confident there are no duplicate IP addresses. Two of my Polycoms have static IPs, well-outside the range of the desk phones. And two other Polycoms in a different office are using DHCP, so there shouldn't been any conflicts.

I suspect there's something wrong or incomplete with the SIP Server config on the 8500. Do you know how SIP registration works? Does a device re-register hourly, or daily, or at log out/in? I'll research it.

I also need to confirm these calls are not going across the WAN and out of our IPFlex circuit.

We see your name all over Tek-Tips.com. Thanks for making time for all of us neophytes.

Bill

 

[bsuggs]

It appears we (NEC) found the fix. Not sure why the SV8500 would default to a 1hr registration, but it did, and the process was killing the call - so it seems. My tests are good, so far. I'm beyond an hour on 2 Polycoms.

Changing the AUACL command to the maximum allowed.