• ×
    Information
    Windows update impacting certain printer icons and names. Microsoft is working on a solution.
    Click here to learn more
    Information
    Need Windows 11 help?
    Check documents on compatibility, FAQs, upgrade information and available fixes.
    Windows 11 Support Center.
  • post a message
  • ×
    Information
    Windows update impacting certain printer icons and names. Microsoft is working on a solution.
    Click here to learn more
    Information
    Need Windows 11 help?
    Check documents on compatibility, FAQs, upgrade information and available fixes.
    Windows 11 Support Center.
  • post a message
Guidelines
The HP Community is where owners of HP products, like you, volunteer to help each other find solutions.
HP Recommended

Kevin,

 

Sounds absolutely like an MTU issue. Probably because broadsoft/polycom don't support PMTUD. Ouch!

 

So one of the modems/routers doesn't support the MTU the broadsoft/polycom keep trying to jam through it like a piehole at a hotdog eating contest and when it comes to polycom.. mums the word. #typical. 

 

There's a hint this is a known issue from a broadsoft manual: "A UDP datagram of 65507 bytes will have to be fragmented into 45 packets ( Max UDP size of 65507 bytes / UDP size per packet of 1480 bytes ~ 45) to be transmitted across a network. With this many number of fragments, customer firewalls or NAT devices may prohibit the entire packet from being delivered to the endpoint."

 

So if you have BLF Issues, think MTU and fragments! Try other modems and networks! 

 

-Brian

 

P.S.

I've seen this MTU issue manifest itself in all kinds of wacky ways. like you send subscribe and get notify but only for <state>terminated<\state> and not for full or whatever the BLF state change is.

 

Some light reading: http://cdn2.hubspot.net/hub/147894/file-1909410432-pdf/docs/Support/Admin_Guides/INVOIP_Connect_-_Mo...

HP Recommended

Hello SIP Shaman,

welcome to the Polycom Community.

Thanks for commenting on these post's with a possible root cause but without any hard evidence brought up to our support team we are unable to verify this. I am not aware if users in this or the other post you replied to have ever done so.

 

I am personally aware of BLF issues and these, to my knowledge , have been addressed in the past when working with our customers.

 

I rather not speculate on the issues discussed within this or the other post you replied to so if you are currently having an BLF issue yourself please work with your reseller so they can raise a ticket with us.


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

------------------------------------------------
Notice: I am an HP Poly employee but all replies within the community are done as a volunteer outside of my day role. This community forum is not an official HP Poly support resource, thus responses from HP Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge.
If you need immediate and/or official assistance for former Poly\Plantronics\Polycom please open a service ticket through your support channels
For HP products please check HP Support.

Please also ensure you always check the General VoIP , Video Endpoint , UC Platform (Microsoft) , PSTN
† The opinions expressed above are the personal opinions of the authors, not of HP. By using this site, you accept the <a href="https://www8.hp.com/us/en/terms-of-use.html" class="udrlinesmall">Terms of Use</a> and <a href="/t5/custom/page/page-id/hp.rulespage" class="udrlinesmall"> Rules of Participation</a>.