RS8234 Mindspeed Technologies, RS8234 Datasheet - Page 165

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

RS8234
ATM ServiceSAR Plus with xBR Traffic Management
6.2.1 Scheduling Priority
6.2.2 Dynamic Schedule Table
28234-DSH-001-B
APPLICATION EXAMPLE: Application-Specific Templates
6.2.1.2 VCC Priority
6.2.1.1 16 Priority
6.2.2.1 Overview
Each template may have different flow control parameters. For instance, a system designer may
wish to configure a VCC traversing a network with all ER switches with a Rate Increase Factor
(RIF) and Rate Decrease Factor (RDF) = 1. However, a VCC traversing a network with switches
doing CI/NI (binary) marking will desire an RIF and RDF
be desired for these VCCs.
Levels + CBR
Assignment
6.2 xBR Cell Scheduler Functional Description
The RS8234 supports 16 scheduling priorities (the “PRI” field in the SEG VCC
Table entry), in addition to the optional CBR service category, with “15” being
the highest priority, down to “0” being the lowest priority. CBR channels are
assigned a priority which is in effect higher than the 16 scheduling priorities dis-
cussed here. From one to 16 of these scheduling priorities can be assigned to
VBR and ABR service classes. The others are shared UBR priorities. The
VBR/ABR priorities must be contiguous within the 16 scheduling priorities, and
thus accessible by an offset pointer. The host sets the offset of the VBR/ABR pri-
orities in the VBR_OFFSET field of SEG_CTRL or SCH_CTRL.
The host assigns the priority of all VCCs, except CBR VCCs, by setting the PRI
field in the Segmentation VCC Table Entry. This priority should be set at
connection setup and should not be changed dynamically.
The xBR Cell Scheduler schedules traffic according to the Dynamic Schedule
Table. The table contains a programmable number of slots, determined by
SCH_SIZE(TBL_SIZE). The duration of a single slot is a programmable number
of System Clocks, set as the number of system clocks per schedule slot, in
SCH_SIZE(SLOT_PER). The Cell Scheduler sequences through this table in a
circular fashion to schedule CBR, VBR, and ABR traffic. UBR traffic is handled
as described in
of each slot, the system designer chooses a range of available rates. This range of
available rates is dictated by the rate at which a single slot is scheduled, the size of
the table, and how many slots in the Dynamic Schedule Table each channel is
assigned.
Mindspeed Technologies
Section
6.2.5. By configuring the number of slots and the duration
1. Thus, separate templates would
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6.2 xBR Cell Scheduler Functional Description
6.0 Traffic Management
6-5