Specifications

WAN services
Issue 1 January 2008 35
● Policy-based routing. The G450 features policy-based routing, which uses a policy list
structure to implement a routing scheme based on traffic source, destination, type, and
other characteristics. You can use policy-based routing lists (PBR lists) to determine the
routing of packets that match the rules defined in the list. Common applications include
separate routing for voice and data traffic, routing traffic originating from different sets of
users through different Internet connections (Internet Service Providers), and defining
backup routes for defined classes of traffic.
● RTP Header Compression. The G450 saves up to 60% of the bandwidth necessary using
RTP compression. It also enhances the efficiency of voice transmission over the network
by compressing the headers of Real Time Protocol (RTP) packets, thereby minimizing the
overhead and the delays involved in RTP implementation.
● TCP Header Compression. The G450 uses Transmission Control Protocol (TCP) header
compression to reduce the amount of bandwidth needed for non-voice data. TCP header
compression can be applied either as part of RTP Header Compression via IPCH, or using
the Van Jacobson method defined in RFC 1144.
● Inter-Gateway Alternate Routing (IGAR). The G450 uses IGAR as a means to use the
PSTN as an alternative to the WAN interface under certain definable conditions. In
providing an alternate routing mechanism, IGAR preserves the internal makeup of the call
so that the call can be successfully terminated to its original internal destination.
Routing features
The G450 has an internal router. You can configure the following routing features on the router:
● Interfaces
● Routing table
● VPN
● GRE tunneling
● DHCP and BOOTP relay
● DHCP server
● DHCP client
● Broadcast relay
● ARP table
● ICMP errors
● RIP
● OSPF
● Route redistribution
● VRRP