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HDX 6000 responds with incorrect transport type in m line - known bug?

Jonathan R
Occasional Visitor

HDX 6000 responds with incorrect transport type in m line - known bug?



I have a case where an HDX 6000 system Release - 3.0.4-20259  responds to an reinvite that includes UDP/BFCP transport type in an m line - the HDX responds with a port and TCP/BFCP in the m line of the 200ok.  The Cisco 8510 MCU running 4.5 (x.xx) does not support BFCP over TCP, only over UDP and it is advertising that in its invite to the HDX endpoint.


This is going against RFC 3264, section 6.1 page 10:


   If the answerer has no media formats in common for a particular

   offered stream, the answerer MUST reject that media stream by setting

   the port to zero.


Instead we should see a reply of the UDP/BFCP transport type and a zero port for the line.


This is causing the call to be dropped when the call flow passes through a Cisco Conductor (xc2.3 / xc2.4) - the B2BUA service catches this m line breaking RFC and will drop the call with a 500 internal server error


I wanted to see if this is a known issue with this software version, and if so is there a fix for this issue where the endpoint incorrectly responds to the m line.


If this is not known I can provide scrubbed logs.



Message 1 of 3
Polycom Employee & Community Manager

Re: HDX 6000 responds with incorrect transport type in m line - known bug?

Hello Jonathan,

welcome to the Polycom Community.

The HDX Software you are using is outdated and is replaced by the latest HDX 3.0.6 software => here <=


There is also a 3.1.5 release for which you require an update key.


Please verify this after updating and if you still see the issue raise this via your Polycom reseller with Polycom support.

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 Poly 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 3
Occasional Visitor

Re: HDX 6000 responds with incorrect transport type in m line - known bug?

Hello Steffen -


I'm the customer Jonathan was working with on this issue.  We were lucky enough to be able to upgrade the HDX 6000 to the latest 3.1.5 software release, and it now responds to the invite as it should, as a result the connection problem we were seeing is gone and we can connect without issue.  So it seems this was fixed somewhere in the HDX software between 3.0.6 and 3.1.5 where it responds to invites properly.



Message 3 of 3