• Supported Platforms
• M10i Routers, M120 Routers, M320 Routers, M7i Routers
• MX240 Routers, MX480 Routers, MX960 Routers
• T640 Routers

• Related Topics
• Locating SIP Servers Using DNS Overview
• clear services border-signaling-gateway name-resolution-cache
• show services border-signaling-gateway name-resolution-cache

Configuring DNS Resolution for Locating SIP Servers

You can configure how the BSG handles the SIP servers in the name resolution cache, and you can specify the methods that the BSG uses to accelerate the DNS name resolution process.

To configure the name resolution cache and the acceleration process:

1. Enter the name resolution cache configuration.
   [edit]user@host# edit services border-signaling-gateway gateway bsg-1 name-resolution-cache
2. Configure a blacklist period; that is, the number of seconds that the BSG marks a SIP server as unavailable after it discovers that the server is down.
   [edit services border-signaling-gateway gateway bsg-1 name-resolution-cache]user@host# set blacklist-period 900
3. Configure the maximum number of SIP servers that can be held in the name resolution cache.
   [edit services border-signaling-gateway gateway bsg-1 name-resolution-cache]user@host# set maximum-records-in-cache 50000
4. Configure the TTL, in seconds, for SIP servers in the name resolution cache.
   [edit services border-signaling-gateway gateway bsg-1 name-resolution-cache]user@host# set maximum-time-in-cache 64000
5. Configure the methods that the BSG uses to accelerate the DNS resolution process.
   [edit services border-signaling-gateway gateway bsg-1 name-resolution-cache]user@host# set accelerations initiate-alternative-queriesuser@host# set accelerations initiate-next-queriesuser@host# set accelerations no-refresh-before-ttl-expiry