PoE network (Sonicwall + Cisco) resets when Polycom SIP phones register

Asked Feb 25 '19 at 18:31

Active Feb 25 '19 at 19:32

Viewed 59 times

We use Polycom 335 and 550 SIP phones in our office and a mix of Sonicwall, Cisco, and Unifi hardware. We're switching SIP providers. Whenever we update any phone's boot server and have it register with our new provider, it works, but for 2-3 minutes our entire wired network comes down. PoE shuts off across the entire office (we can tell because all PoE devices turn off) and all wired devices lose connectivity.

I believe both of the Cisco PoE switches are restarting. I believe this because our wireless network, which is on a separate Unifi switch, stays up and connected to internet during this time while all the wired devices go down.

Our hardware is:

Sonicwall NSA 3650
Sonicwall SMA 400
Cisco PoE switches
Unifi switch + access points

The network is:

ISP -> NSA 3650 as router -> SMA, Cisco switches, and Unifi switches plugged into the NSA 3650.

Has anybody seen this before? Any idea what the cause is? We don't want to bring down our network every time we register a new phone.

Thanks!

edited Feb 25 '19 at 19:32

asked Feb 25 '19 at 18:31

Matt

A diagram of your network would be helpful. Are all the PoE switches restarting? – Ron Trunk Feb 25 '19 at 18:36
@RonTrunk thanks, good suggestions. I just added that detail to the post. – Matt Feb 25 '19 at 19:33
Are all PoE switches restarting? – Ron Trunk Feb 25 '19 at 19:49
@RonTrunk as best I can tell, yes, as all the devices across both are losing PoE. – Matt Feb 25 '19 at 20:41
That sounds more like a power problem. I can't think of anything that would cause more than one switch to reboot. – Ron Trunk Feb 25 '19 at 20:43
Are you able to login to the Cisco switches and confirm in the logs that they are indeed restarting etc – tegbains Feb 25 '19 at 22:04
@Ron Trunk I don’t believe this is a power problem, because it’s only when the phones register with the SIP provider that it happens. If I leave them on without initiating a registration then there’s no restart. – Matt Feb 27 '19 at 03:16
@tegbains No, I’ll try that! – Matt Feb 27 '19 at 03:21

PoE network (Sonicwall + Cisco) resets when Polycom SIP phones register

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