Not sure on this one where to look, so I'll just ask:
Here is a config at a client site:
* Hosted PBX on Asterisk
* 20 Snom 320s, all using BLF for extensions (average 10 extensions subscribed to)
* 8 Snom 320s with Expansion module, using BLF for about 26 extensions
* All traffic going through a Cisco 1721 Router to a T1 WAN using NAT Overload
So here is what happens: As the phones are used, and the SIP Notify messages traverse the NAT in the router, the router's free memory drops rapidly to the point where it kills funcitonality in the router in about 3 hours. It does not appear to come back in time, the router MUST be restarted to regain the free memory.
If BLF extension monitoring is NOT enabled on any of the phones, the router does not display this 'memory leak' behavior at all.
I have also tried this with a Cisco 2600XM router with similar results.
I see this in 12.3 AND 12.4 codebases. Has anyone out there seen this before and knows a fix? We use the 1721's as our end-point T1 router for several customers, and are aware this could very well be a Cisco bug, but I wanted to see what the consensus was.
Any ideas?
stop using nat, replace your
stop using nat, replace your cisco with a edgemarc 45xx series that supports t1 interface and use its built in sip proxy (they call it a voip alg but its really a full fledged proxy). Set your phones to use the proxy as its outbound sip proxy. 28 phones is a lot of phones for a single T1 interface esp if its also supposed to be doing non-voice traffic as well.
I figure we'd have to start
I figure we'd have to start moving toward something newer, since the 1721 & 2600 are E.O.L.. Just thought it odd that the breaking factor is the (admittedly vast volume of) NOTIFY messages.
We ended up putting a netgear router in to handle the NAT and it seems to do the trick, depending on which model (MUCH of the netgear stuff is total CRAP, but in this case it seemed to work). Its not an elegant solution so I was starting to see what the deal was with others.
Its a holiday, and I'm probably being dense, but not sure how we would move away from NAT, since we assign our customers a /30 public IP?
read some of my other posts
read some of my other posts regarding a sip proxy at the CPE and how it eliminates NAT
I should say, Hosted PBX with Thirdlane MTE...