TGM550 IP Addressing Guidelines

For operational purposes, the TGM550 is considered as a host on the Services Router. Hence, the TGM550 needs to be assigned an IP address that is reachable both externally and internally from the Services Router. The TGM550 uses this IP address to identify itself when communicating with other devices, particularly the Media Gateway Controller (MGC).

To assign the IP address for the TGM550, you configure the destination address on the vp-pim/0/0 interface. For information about configuring the vp-pim/0/0 interface, see Configuring the VoIP Interface (Required).

When you specify the IP address for the first time, or modify an existing IP address, the TGM550 is reset when you commit the configuration.

To enable easier administration of the TGM550, Juniper recommends the following guidelines for assigning the IP Address for the TGM550:

• Assign an address from one of the subnets that is already configured in the branch office where the Services Router is installed.
• Decide on a block of IP addresses for VoIP services and assign an IP address from that block to the TGM550.
• Do not assign the following IP addresses to the TGM550:
  • A broadcast address (255.255.255.255)
  • A class E address (240.0.0.0 to 255.255.255.254)
  • A loopback address (127.0.0.0 to 127.255.255.255)
  • A multicast address (224.0.0.0 to 239.255.255.255)
• If the assigned IP address is on the same Ethernet subnet as that of a Fast Ethernet or Gigabit Ethernet interface configured for VoIP connectivity, configure proxy Address Resolution Protocol (ARP) or unrestricted proxy ARP on the Fast Ethernet or Gigabit Ethernet interface. We recommend that you configure proxy ARP on the Fast Ethernet or Gigabit Ethernet interface.

For information about configuring proxy ARP and unrestricted proxy ARP, see the following topics:

• Configuring Proxy ARP
• Configuring Unrestricted Proxy ARP