Technical data
24 Brocade ServerIron ADX Advanced Server Load Balancing Guide
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SIP SLB over TCP
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SIP SLB over TCP options
The following section describes SIP SLB over TCP options.
Configuring periodic keepalive
Use the keepalive commands to periodically check the real server state after it is brought up. You
can enable keepalive from the port profile configuration or from the real server port configuration.
SIP port profile configuration
Use the udp keepalive protocol sip command to configure keepalive from the SIP port profile
configuration.
ServerIronADX(config)#server port sip
ServerIronADX(config-port-sip)#udp keepalive protocol sip
Syntax: udp keepalive protocol sip
Real server port configuration
Use the port sip keepalive command to configure keepalive from the real server port configuration.
ServerIronADX(config)#server real proxy-server-1
ServerIronADX(config-rs-proxy-server-1)#port sip keepalive
Syntax: port sip keepalive
Configuring a DSCP value for SIP health checks
During periods of network congestion, SIP health checks do not get high enough priority in a
network, which causes servers to fail needlessly. Consequently, high-priority services such as VoIP
can suffer service interruptions. This feature allows you to set a Differentiated Services Code Point
(DSCP) value in the IP header of SIP health-check packets. The network can then be configured to
grant sufficient priority to the SIP heath check packets to ensure robust service.
In the following example, a DSCP value of 46 is set for health check packets sent to SIP proxy
service 10.1.9.5:SIP.
ServerIronADX(config)#server real si-server 10.1.9.5
ServerIronADX(config-rs-sip-server)#port sip sip-proxy-server
ServerIronADX(config-rs-sip-server)#port sip hc-dscp-mark 46
Syntax: port sip hc-dscp-mark DSCP-value
The DSCP-value variable can be set to a value from 0 through 63.
NOTE
When this command is configured for real service ports other than that of a SIP service, the value
is ignored during health check. Examples include: sip-proxy-server, sip-redirect-server, sip-registrar,
and sip-both-registrar-proxy-server.