Technical data

20 Brocade ServerIron ADX Advanced Server Load Balancing Guide
53-1003441-01
SIP SLB over TCP
1
Client side: Connection reuse with Mega Proxy client
Figure 7 shows several SIP requests being initiated by a Mega Proxy client. The Mega Proxy uses a
single TCP connection to send all these requests. Each of these requests is identified using a
unique SIP Call-ID. The ServerIron ADX separates these requests and load balances them among
different back-end proxy servers.
FIGURE 7 Reuse of TCP connection
Server-side connection: With source NAT
If source NAT is enabled, then the ServerIron ADX uses source NAT IP addresses and ports for
establishing connections with proxy servers.
Server-side connection: Without source NAT
A ServerIron ADX may be configured with a maximum number of TCP connections to a specific
proxy server.
If source NAT is disabled on the ServerIron ADX, then the ServerIron ADX establishes new TCP
connections based on the connection reuse setting:
• Connection reuse disabled: If a new SIP request is received and the configured maximum
number of server connections has been reached, then ServerIron ADX drops any new request.
This is the default behavior.
• Connection reuse enabled: If a new SIP request is received and the configured maximum
number of server connections has been reached, then ServerIron ADX reuses an established
connection to process the client request.
NOTE
With either setting, the client identity (IP address and port) is preserved because source NAT is not
enabled.