AudioCodes Mediant 4000 SBC User Manual page 955

CHAPTER 60 Configuration Parameters Reference
configure voip > sip-
definition proxy-and-
registration > add-init-
rte-hdr
[InitialRouteHeader]
configure voip > sip-
definition proxy-and-
registration > ping-pong-
keep-alive
[UsePingPongKeepAlive]
configure voip > sip-
definition proxy-and-
registration > ping-pong-
keep-alive-time
[PingPongKeepAliveTime]
Parameter Description
■ [1] Enable
When the device sends a REGISTER message, the
Route header includes either the Proxy's FQDN, or IP
address and port according to the configured Proxy Set,
for example:
Route:
<sip:10.10.10.10;lr;transport=udp>
or
Route: <sip: pcscf-
gm.ims.rr.com;lr;transport=udp>
Enables the use of the carriage-return and line-feed
sequences (CRLF) Keep-Alive mechanism, according
to RFC 5626 "Managing Client-Initiated Connections in
the Session Initiation Protocol (SIP)" for reliable,
connection-orientated transport types such as TCP.
■ [0] Disable (default)
■ [1] Enable
The SIP user agent/client (i.e., device) uses a simple
periodic message as a keep-alive mechanism to keep
their flow to the proxy or registrar alive (used for
example, to keep NAT bindings open). For connection-
oriented transports such as TCP/TLS this is based on
CRLF. This mechanism uses a client-to-server "ping"
keep-alive and a corresponding server-to-client "pong"
message. This ping-pong sequence allows the client,
and optionally the server, to tell if its flow is still active
and useful for SIP traffic. If the client does not receive a
pong in response to its ping, it declares the flow "dead"
and opens a new flow in its place. In the CRLF Keep-
Alive mechanism the client periodically (defined by the
PingPongKeepAliveTime parameter) sends a double-
CRLF (the "ping") then waits to receive a single CRLF
(the "pong"). If the client does not receive a "pong"
within an appropriate amount of time, it considers the
flow failed.
Note: The device sends a CRLF message to the Proxy
Set only if the Proxy Keep-Alive feature
(EnableProxyKeepAlive parameter) is enabled and its
transport type is set to TCP or TLS. The device first
sends a SIP OPTION message to establish the
TCP/TLS connection and if it receives any SIP
response, it continues sending the CRLF keep-alive
sequences.
Defines the periodic interval (in seconds) after which a
"ping" (double-CRLF) keep-alive is sent to a
proxy/registrar, using the CRLF Keep-Alive
mechanism.
The default range is 5 to 2,000,000. The default is 120.
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Mediant 4000 SBC | User's Manual