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Network is down issue (Random) in Polycom IP 331 / 5000 / 6000 phones

Ravikiran DP
Occasional Visitor

Network is down issue (Random) in Polycom IP 331 / 5000 / 6000 phones


I have around 1200 polycom ip 331 phones deployed in my network. The phones gets IP address and registers properly with the Call manager and works well. But, all of a sudden for about 1 minute the phones shows "network is down" error and again resumes. If the phone is active (on call) the ongoing call goes blank and resumes once the error goes off. This is happening randomly across all the phones in my network which includes IP 331, 5000 & 6000 phones.


I had kept continuous ping to the phones ip to understand if the phone is actually going out of network, However I did not find any packet drops when the issue occured. I am able to see the response for all the ICMP packets. Upon escalating this issue to my network team, they are coming back saying as there is no loss in the ping, there is no issue with network.


Can somebody please tell me what are the possible reasons why polycom phones display network is down error? while this error occurs polycom phone even gives the beep sound which indicates the network went down.


Below mentioned is the firmware details, Please suggest.


UC Software Version & BootROM Software Version

Message 1 of 3
Polycom Employee & Community Manager

Re: Network is down issue (Random) in Polycom IP 331 / 5000 / 6000 phones

Hello @Ravikiran DP,

welcome to the Polycom Community.


First of all I would suggest you use the right software.

The community's VoIP FAQ contains this post here:

Jun 30, 2015 Question:What is the difference using the UC Software 4.0.0 for compatible SoundPoint or SoundStation IP Phones?

Resolution: Please always check the release Notes or

Software Version  Call Server
4.0.X SIP Only
4.1.X LYNC Only


Please ensure you always check the community FAQ and/or utilize the community search before posting any new topics or follow up post’s.


The next step would be a spanned port and monitor the phone via wireshark.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services

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. My official "day" Job is 3rd Level support at Poly but I am unable to provide official support via the community.


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 3
Ravikiran DP
Occasional Visitor

Re: Network is down issue (Random) in Polycom IP 331 / 5000 / 6000 phones

Dear Steffen,


Thanks for sharing the supported firmware. I will try installing 4.0.X in some phones and monitor the same for 2-3 days and update.

Message 3 of 3