[VoiceOps] Polycom BLF w/ SBC

Jay Hennigan jay at west.net
Mon Apr 27 13:52:04 EDT 2015

On 4/27/15 10:03 AM, David Wessell wrote:
> HI All,
> Has anyone ever had luck with getting Polycom BLF to work through a
> non-Broadworks SBC?

We are using Sansay SBCs, Polycom phones with BLF, and Broadworks. No 
issues with the SBCs, but make sure that if you have a SIP ALG or NAT 
box it needs to be able to reassemble large UDP SIP fragmented packets. 
Adtran 3120 is a problem, for example. Adtran TA900e series are fine.

In some cases if the CPE isn't under your control, changing transport to 
TCP will resolve the issue.

BLFs are chatty and if you have several on a phone you may be looking at 
three or even four 1500-byte fragments per message.

Jay Hennigan - CCIE #7880 - Network Engineering - jay at impulse.net
Impulse Internet Service  -  http://www.impulse.net/
Your local telephone and internet company - 805 884-6323 - WB6RDV

More information about the VoiceOps mailing list