RS8234 Mindspeed Technologies, RS8234 Datasheet - Page 186

• Manufacturer Part Number: RS8234
• Description: Atm Servicesar Plus With Xbr Traffic Management
• Manufacturer: Mindspeed Technologies

6.0 Traffic Management
6.3 ABR Flow Control Manager
Figure 6-15. Steady State ABR-ER Cell Stream
Figure 6-16. Cell Type Interleaving on ABR-ER Cell Stream
6-26
Note: Nominally, Nrm = 32
FW_RM BW_RM
(SCH_STATE)
State Table
SEG VCC
characteristics of ABR connections, all connections will not maintain a steady
state sequence. Furthermore, since it is an immature specification, the rules for
cell interleaving of in-rate cell streams may be modified slightly.
specification on cell stream interleaving. This Cell Type Decision algorithm
makes on-the-fly decisions concerning which type of cell to send, based on the
current state of the connection. Figure 6-16 shows a block diagram of the
algorithm. The ABR Flow Control Manager chooses a cell type based on a Cell
Decision Table and the VCC state. The segmentation coprocessor then formats
the appropriate cell type and sends it on the ABR in-rate cell stream. Note that the
ABR Flow Control Manager may choose to send no cell. This occurs when the
VCC has no user data to segment.
user can modify it to optimize performance or react to changes in the ABR
specification. Furthermore, multiple tables allow groups of VCCs to be tuned for
different network policies.
One FORWARD_RM Cell Period
Unfortunately, due to the asynchronous, asymmetrical, and fluctuating
The RS8234 provides a programmable mechanism to comply with TM 4.1’s
Since the Cell Decision Table template resides in SAR shared memory, the
Data Cell
Forward RM
Backward RM
None
Mindspeed Technologies
Nrm Data Cells
Manager
Control
Flow
ABR
Cell Type
Action
ATM ServiceSAR Plus with xBR Traffic Management
Decision
Table
Cell
™
FW_RM
ABR-ER Cell Stream
BW_RM
28234-DSH-001-B
RS8234
100074_054
100074_055