Juniper JUNOSE 11.2.X MULTICAST ROUTING, Руководство по настройке

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Bandwidth and Line Rate Considerations
When the GE-HDE line module is installed in the ERX1440 router, it delivers full bandwidth
of 4 Gbps per line module (2 Gbps at the ingress and 2 Gbps at the egress) only when
installed in slot 2 or slot 4, and when the SRP-40G+ module is used in the router. When
the module is installed in any other ERX1440 slot, it delivers a maximum bandwidth of
2 Gbps per line module (1 Gbps maximum at the ingress and 1 Gbps maximum at the
egress). Therefore, of the maximum 96 possible ports for the module in an ERX1440
chassis (that is, eight ports in each of 12 slots), full bandwidth is delivered only on a
maximum of 16 ports (those in slots 2 and 4).
When the GE-HDE line module is installed in either the ERX1440 or the ERX310 router
and all ports are active, line rate performance is achieved only with packets that are
174 bytes or larger. The module might not achieve line rate with packets that are smaller
than 174 bytes.
Table 14 on page 173 lists the average data rate on the GE-HDE line module and GE-8 I/O
module combination when installed in an ERX310 router or in slots 2 or 4 of an ERX1440
router.
Table 14: Average Data Rate for ERX310 router or in Slots 2 or 4 of an
ERX1440 router
Average Data Rate per
GE-HDE Line Module Average Data Rate per GE-8 I/O
Module (> 174 Byte Packets)
Port Combination
250 Mbps per port 250 Mbps per port Ports 1–8
500 Mbps per port 500 Mbps per port Any four ports
1 Gbps per port 1 Gbps per port Any two ports
Table 15 on page 173 lists the average data rate on the GE-HDE line module and GE-8 I/O
module combination when installed in all other slots on the ERX1440.
Table 15: Average Data Rate When Installed in All Other Slots on an
ERX1440 router
Average Data Rate per
GE-HDE Line Module Average Data Rate per GE-8 I/O
Module (> 174 Byte Packets)
Port Combination
125 Mbps per port 125 Mbps per port Ports 1–8
250 Mbps per port 250 Mbps per port Any four ports
500 Mbps per port 500 Mbps per port Any two ports
Managing High-Density Ethernet
The overall data rate for the GE-HDE line module is 2 Gbps; therefore, the I/O module
becomes highly oversubscribed because of the wire rate of the line module. The data
173 Copyright © 2010, Juniper Networks, Inc.
Chapter 5: Configuring Ethernet Interfaces