User`s guide
Polycom VVX Expansion Module Administrator’s Guide Addendum  UC Software 4.1.6 
Polycom, Inc.  56 
Parameter 
Permitted Values 
Default 
voIpProt.SIP.outboundProxy.failOver.onlySignalWithRegistered 
0 or 1 
1 
When set to 1, and the reRegisterOn and failRegistrationOn parameters are enabled, no signaling is 
accepted from or sent to a server that has failed until failback is attempted or failover occurs. If the phone 
attempts to send signaling associated with an existing call via an unregistered server (for example, to resume or 
hold a call), the call ends. No SIP messages are sent to the unregistered server. When set to 0, and the 
reRegisterOn and failRegistrationOn parameters are enabled, signaling is accepted from and sent to a 
server that has failed (even though failback hasn’t been attempted or failover hasn’t occurred). This parameter 
overrides voIpProt.server.x.failOver.onlySignalWithRegistered. 
voIpProt.SIP.outboundProxy.failOver.reRegisterOn 
0 or 1 
0 
This parameter overrides the voIpProt.server.x.failOver.reRegisterOn. When set to 1, the phone 
attempts to register with (or via, for the outbound proxy scenario) the secondary server. If the registration 
succeeds (a 200 OK response with valid expires), signaling proceeds with the secondary server. When set to 0, 
the phone won’t attempt to register with the secondary server, since the phone assumes that the primary and 
secondary servers share registration information. 
voIpProt.SIP.outboundProxy.transport 
DNSnaptr, 
TCPpreferred, 
UDPOnly, TLS, 
TCPOnly 
DNSnaptr 
The transport method the phone uses to communicate with the SIP server. 
- Null or DNSnaptr  if reg.x.outboundProxy.address is a hostname and 
reg.x.outboundProxy.port is 0 or Null, do NAPTR and then SRV lookups to try to discover the transport, 
ports and servers, as per RFC 3263. If reg.x.outboundProxy.address is an IP address, or a port is given, 
then UDP is used. 
- TCPpreferred  TCP is the preferred transport, UDP is used if TCP fails. 
- UDPOnly  Only UDP is used. 
- TLS  If TLS fails, transport fails. Leave port field empty (defaults to 5061) or set to 5061. 
- TCPOnly  Only TCP is used. 
voIpProt.SIP.pingInterval 
0 to 3600 
0 
The number in seconds to send ping message. This feature is disabled by default. 
voIpProt.SIP.pingMethod 
PING, OPTIONS 
PING 
The ping method used. 
voIpProt.SIP.presence.nortelShortMode
1
0 or 1 
0 
Different headers sent in SUBSCRIBE when used for presence on an Avaya (Nortel) server. Support is indicated 
by adding a header Accept-Encoding: x-nortel-short. A PUBLISH is sent to indicate the status of the 
phone. 
voIpProt.SIP.requestValidation.digest.realm
1
A valid string 
PolycomSPIP 
Determines the string used for Realm. 










