[Freeswitch-users] TCP ACK Ping

[Spencer Thomason]

Hello all,
I have been doing some experimentation migrating several phones from UDP 
to TCP SIP to address MTU issues with BLF NOTIFYs.  Mostly everything is 
working great except for Polycom handsets running UC v4.  (Note that I 
did not test any v3 phones.)  The phones are behind NAT and Freeswitch 
is on a public IP.  The phones periodically send a TCP ACK ping to 
Freeswitch which goes unanswered and then phone then tears down the TCP 
connection.  I'm not at all a TCP expert but should Freeswitch be 
responding to this unsolicited ACK?  I have tried in vain to disable 
these keepalives from the Polycoms.  Has anyone else encountered this 
behavior?

Thanks in advance,
Spencer