Hitachi GR2000 - Manual (Page 221)

and GR2000-4. On these router models, NIF0 and NIF2 connect with each other v
bus, and NIF1 and NIF3 connect with each other via the other bus. The aggregat
line speed of NIF0 and NIF2, and that of NIF1 and NIF3, must not exceed 600 Mb
Figure 5-19 illustrates this shared-bus structure. Detailed description follows.
Table 4-23 Restriction on Aggregate Line Speed for GR2000-4S and GR2000-4
Condition Max. Aggregate Line Speed Mbps
Per Bus (NIF0+NIF2 or NIF1+NIF3) 600
Per device 1,200
RP
RM-IO
NIF 3 NIF 2
NIF 1 NIF 0
Up to 600 Mbps
on same bus p to 600 Mbps
n same bus