PM7323 Datasheet, PDF (185/219 Pages) PMC-Sierra, Inc – ROUTING CONTROL, MONITORING, & POLICING 200 MBPS

STANDARD PRODUCT
PM7323 RCMP-200
DATASHEET
PMC-960543
ISSUE 2
ROUTING CONTROL, MONITORING, & POLICING
200 MBPS
Table entries must be examined to isolate the VC to be removed. Once
identified, the linked list is modified to bypass the VC.
The steps required to remove one element of a multicast are:
1. Find the location of the Secondary Search Table entry pointing to the head of
the multicast linked list.
2. Traverse the linked list to find the VC to be removed.
3. Modify the Secondary Search Table entry pointing to the node being removed
to point to the node following the one being removed, as illustrated below.
The VC is now considered unprovisioned.
Figure 14 -
BEFORE
AFTER
ones 1 ^x 1 ^c
VC
TABLE
Ent r y
ones 1 w 1 d
VC
TABLE
Ent r y
01 y1 0
VC
TABLE
Ent r y
ones 1 x 1 d
Tag as free.
VC
TABLE
Ent r y
ones 1 w 1 d
VC
TABLE
Ent r y
0 1y 1 0
VC
TABLE
Ent r y
Two special cases need to be accommodated:
i. The VC to be removed is the tail of the list. In this case, the parent node
becomes the new tail and its Select field should be modified to be all zeroes.
ii. The removal leaves only one VC in the multicast. The pointer to the head of
the list, should be modified to point to the surviving VC Table Record. Two
Secondary Search Table entries are freed up.
4. Tag the removed Secondary Search Table entry (or entries) as free.
Proprietary and Confidential to PMC-Sierra, Inc.
174
and for its Customer’s Internal Use.