cn8237 Mindspeed Technologies, cn8237 Datasheet - Page 191

• Manufacturer Part Number: cn8237
• Description: Atm Oc-12 Servicesar Plus With Xbr Traffic Management
• Manufacturer: Mindspeed Technologies

CN8237
ATM OC-12 ServiceSAR Plus with xBR Traffic Management
Figure 6-20. ER RATE_INDEX Candidate Selection
28237-DSH-001-C
ER
two, each of which are
RATE_INDEX in the VCC’s SCH_STATE entry. Then, the CN8237 uses this
RATE_INDEX to point to the corresponding appropriate Rate Decision Block
(RDB) and, as specified in TM 4.1, updates the VCC’s rate parameter with the
RDB’s I and L parameters.
coprocessor passes the CI, NI, and ER fields from the RM cell to the ABR Flow
Control Manager via the RSM/SEG Queue. The Flow Control Manager uses the
ABR Rate Decision table and the Exponent table, both programmable
components of an ER template, to calculate the two RATE_INDEX candidates,
each of which are
candidate. Then, the CN8237 updates the VCC’s rate parameters with the newly
selected rate index. This rate index points to a Rate Decision Block whose I and L
parameters establish the new rate. The Cell Scheduler uses the updated rate to
schedule all future traffic until the next rate update.
Figure 6-20
Once both candidates are identified, the CN8237 selects the smaller of the
Figure 6-21
Mindspeed Technologies
CANDIDATE
INDEX
illustrates the ER RATE_INDEX candidate selection.
provides a block diagram of this process. The reassembly
ER
MCR. The min() function is applied to select a winning
MCR. The winning candidate then replaces the current
CONNECTION STATE (RATE_INDEX)
™
6.3 ABR Flow Control Manager
6.0 Traffic Management
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