IBM 9077 Router User Manual


 
36 IBM 9077 SP Switch Router: Get Connected to the SP Switch
Figure 18. System RAM
2.3.5 Characteristics of GRF Media Cards
All GRF media cards (media adapters) are self-contained and independent of
other media adapters.
Each media card has an onboard processor that is responsible for IP
forwarding on the media adapter.
Each media card has two independent memory buffers, a 4 MB send buffer
and a 4 MB receive buffer. These buffers are necessary to balance the speed
differences between the media adapters, because they have different transfer
rates.
Each onboard processor has local memory that can contain a local route
table with up to 150,000 entries, to be used for routing on the media adapter.
Because these route entries are in local memory, access to them is very fast.
When the media adapter is started up, it gets its initial route entries from the
IP Switch Control Board.
2.3.6 SP Switch Router Adapter
The GRF supports a number of media adapters. Figure 19 describes the SP
Switch Router Adapter in detail. This adapter allows the GRF to connect
directly into the SP Switch.
64MB RAM
64MB RAM
64MB RAM
64MB RAM
32MB
(fixed size)
20MB
8-12MB
(fixed size)
- System software
- Config files
- Gated binary
- Route table
- Kernel runs
- Gated runs
= expandable area of RAM