Lexmark IBM 9077 Network Router User Manual


 
66 IBM 9077 SP Switch Router: Get Connected to the SP Switch
2.7 Conclusion
The SP Switch Router 9077-04S has an aggregate bandwidth of 800 MB/s.
An SP wide node by contrast is capable of no more than about 65 MB/s of
sustained throughput. A wide node’s CPU hits a wall at about 5000
packets/second, whereas the 9077 is capable of an aggregate of 2.8 million
packets/second. All this is achieved in part because of the non-blocking
crosspoint switch with four 100 MB/s, full duplex connection points. This
enables multiple paths to operate at full speed simultaneously.
Unlike the SP nodes, the SP Switch Router is designed with high availability
in mind. It provides balanced, fully redundant power supplies that can be hot
swapped in case of failure. It provides the ability for redundant paths to an SP
Switch to be configured on a single 9077; with dynamic routing protocols, a
second 9077 can be used to provide a backup path in case of system failure
of the primary router. In either case, each media card is hot swappable and
autoconfigured after the initial install has been completed.
With its high port count on interfaces such as FDDI and Ethernet and its
highly scalable performance, the SP Switch Router provides a very cost
effective solution. With each media card you get a nearly linear scaling of
performance with very little cost increase. An SP node by comparison runs
out of CPU cycles and/or slots very quickly requiring the purchase of another
entire node.
Since the 9077 (or rather the Ascend GRF) was originally designed for ISP’s,
it has a full set of protocols, including dynamic routing protocols such as
OSPF, BGP4 and RIPv2. It also has the memory required to hold up to
150,000 routes and the speed to access a table of this size without
performance degradation. Support for media types not supported by the SP
nodes also enables the SP to now be connected into networks that will be
important for its future. These include support for HSSI and Sonet, which are
important for the SP’s ever-growing role as a Web server or online
transaction manager.