HP ProCurve 1600M Reviewer's Manual - Page 10

Browse online or download pdf Reviewer's Manual for Switch HP ProCurve 1600M. HP ProCurve 1600M 27 pages. Redundant power supply
Also for HP ProCurve 1600M: Specification Sheet (12 pages), Read Me First (8 pages), Supplementary Manual (2 pages), Supplementary Manual (2 pages), Installation Manual (28 pages), Installation Manual (36 pages), Installation Manual (28 pages), Quick Setup Manual (2 pages), Quick Setup Manual (4 pages), User Manual (8 pages), Manual Supplement (28 pages), Read Me First (16 pages), Installation And Removal (2 pages), Installation Manual (12 pages), Planning And Implementation Manual (40 pages), Product End-Of-Life Disassembly Instructions (2 pages), Installation Manual (46 pages), Diagnostics Manual (2 pages), Disassembly Instructions (2 pages)

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HP ProCurve Routing Switch 9308M / 9304M Reviewer's Guide

2.2.4 Forwarding Engine

The forwarding engine, a custom ASIC present on each module, uses the information in the FID to

actually move the packets to and from either external ports or the backplane switch fabric via the

shared memory. The forwarding engine also determines the priority queue (described in the next

section) designation for outbound packets. The forwarding engine has its own separate data path to

the packet processors to make packet processing time as short as possible.

2.2.5 Priority Queues

Priority queues form part of the QoS implementation in the routing switch. Each external port on a

module has 4 priority queues that define the order outbound packets will be sent to that port. There are

also 4 priority queues on the module for each of the other modules installed in the chassis. These are

used for packets destined to travel the backplane to another module. The priority queues themselves

only contain the SMIDs as pointers to the actual packets in shared memory.

These priority queues map into the priority designation of 802.1p. Since 802.1p has 8 levels of priority

possible, 802.1p priority levels 0 and 1 map to the module priority of 0 (lowest), 802.1p levels 2 and 3 to

module priority 1, and so on. Packets without any 802.1p tagging are normally assigned module

priority 0, unless the port priority factors have been modified through user configuration. The priority

queues are managed through a fair-weighted queuing algorithm that prevents any priority queue from

getting starved due to high traffic levels in other queues.

Through user configuration, priority of packets can be changed based on the packet's MAC address,

VLAN affiliation, port the packet came in on, IP address, or IP port number.

2.2.6 System Management Interface

The System Management Interface, present on the management card, stores and maintains the port and

system-level master configuration tables, routing tables, Layer 2, Layer 3, and Layer 4 address tables,

and all FID registers. Packet functions requiring processor attention, such as AppleTalk routing or

broadcast packet handling are also handled through this interface.

Communication from the individual module packet processors to the System Management Interface is

done through the management bus, a control path distinct from the packet data path. Any modification

of the FID for those packets requiring additional central processor attention are also handled through

the management bus. The central processor runs at 240 MHz.

The System Management Interface has 32 MB of DRAM memory available. This memory is used for

switch tables, such as routing tables, ARP cache and MIB tables. At factory default, many of the table

sizes are less than their maximum in order to conserve memory. Tables can be resized through user

configuration, if necessary. Default and maximum values are given in this guide for some tables.

2.2.7 Backplane Design

The modules are interconnected through a backplane crosspoint

Slot 1

switch matrix, allowing packets a direct path to their destination

8 Gbps fdx

module. Each module in the chassis has an 8 Gbps path in both

directions to this matrix.

Slot 2

Slot 3

The advantage of a crosspoint matrix is that all modules can send

packets to every other module simultaneously. The crosspoint

matrix can handle about 22 Mpps in the 9304M and 44 Mpps in the

9308M.

Slot 4

Revision 4.0 – 4/1/1999

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