Technical data

ServerIron ADX Advanced Server Load Balancing Guide 23
53-1002435-03
Configuring SIP SLB
1
Real server port configuration
To configure keepalive from the real server port configuration, use the following commands.
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 1.1.9.5:SIP.
ServerIronADX(config)# server real si-server 1.1.9.5
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.
Rehashing the SIP hash table
This section describes the commands for hash table management.
Manual rehash
Use the following command to manually rehash the hash table.
ServerIronADX(config)# server sip-hash-table-rehash vip1 sip registrar-table
Syntax: server sip-hash-table-rehash <virtual server name> <virtual port> <registrar-table |
proxy-table>
Automatic rehash
Use the following command to set the hash table idle time for real server replacement.
ServerIronADX# server sip-hash-table-idle 300000
Syntax: server sip-hash-table-idle <sip-hash-table-idle-time>
The <sip-hash-table-idle-time> variable is measured in seconds. The default is 1000 seconds.