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Polycom SIP 331 phones not getting network when connected to POE switch

Occasional Contributor

Polycom SIP 331 phones not getting network when connected to POE switch

Phone : Polycom SIP 331

Firmware : 2345-12365-001.sip.ld


Issue : We have a Linksys E1200 firewall and 6 Polycom SIP 331 phones connected to a D-link DES 1210-28 P Power over Ethernet switch. The phones are set to accept IPs via dhcp. Initially, all the phones got IPs and were communicating with our server fine. Now intermittently, all the phones would loose network inspite of having a private IP from the firewall. Sometimes powercycling the POE switch would resolve the issue. A couple of days ago, power-cycling the POE did not resolve it and after we changed all the IPs on the Polycoms to static IPs, the phone started communicating again. There is nothing else connected to the POE switch besides the firewall and Polycom Phones. 


Questions :


1) Is there a setting on the phones that needs to be adjusted on Polycom Phone to resolve this dhcp issue?

2) Are Polycom phones compatible with brand of POE switch. Has there been issues in the past?

3) Any idea what is causing this?


Thank You for time,





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Polycom Employee & Community Manager

Re: Polycom SIP 331 phones not getting network when connected to POE switch

Hello Hashim,


PoE is an industry standard and there would not be tests against individual PoE switches.


The issue you are having leaves a few questions open.


  • What do you mean by loosing their network?
    Can you still ping the phone or access the web interface or are the phones reporting "Network Down" ?
  • What Software Version are you running?
    As it is an IP 331 you can and should run UCS 4.0.3 at least.

You may want to setup a mapped port so you can run a wireshark trace and check the traffic between the Phone and the Switch.


Best Regards


Steffen Baier

The title Polycom Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer.


Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 2 of 2