C H A P T E R 23 Configuring The Atm Traffic-Shaping Carrier Module; Hardware And Software Restrictions; Hardware Restrictions - Cisco Catalyst 8540 MSR Configuration Manual

Chapter 23 Configuring the ATM Traffic-Shaping Carrier Module
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Hardware and Software Restrictions

This section lists the hardware and software restrictions for the TSCAM.

Hardware Restrictions

The following hardware restrictions apply to the TSCAMs of the Catalyst 8510 MSR and
LightStream 1010 ATM switch:
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Software Restrictions
The following software restrictions apply to the TSCAMs of the Catalyst 8510 MSR and
LightStream 1010 switch routers:
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Note
OL-7396-01
Traffic shaping for VBR and best-effort traffic
Up to four TSCAMs in a chassis
Up to four ports 256K cell buffers share
Although the TSCAM occupies one full slot on the switch router, the traffic-shaping functionality
can only be applied to ports on subcard 0.
The TSCAM accommodates only OC-3, T1, E1, DS3, or OC-12 port adapters.
Only three traffic classes can be shaped on the OC-3 port adapter.
The TSCAM is not compatible with the FC-PCQ feature card.
Successive OIR operations must have a delay of 1 minute between them, especially reseating a
TSCAM itself or reseating the port adapter in subslot 0 in the TSCAM.
Each TSCAM requires 2 MB of continuous main memory availability in the switch.
Well-known VCs on an interface that is enabled for VBR traffic shaping will be automatically shaped at
the maximum cell rate of that interface. Changing shaping properties for these VCs is not allowed.
Any changes to the shaping configurations are supported across switch reloads.
Tag switching VCs and Multiprotocol Label Switching (MPLS) VCs are not currently supported.
The maximum rate to which a VC can be shaped on an OC-12 interface is 595,085 Kbps
The minimum rate that a VC can be shaped is as follows:
36 Kbps for DS3, E3, T1, E1, and OC-3 interfaces
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145 Kbps for OC-12 interfaces
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When VBR connections are shaped using sustainable cell rate (SCR), PCR, and maximum burst size
(MBS), the burst tolerance computed always rounds up to the next higher value that conforms to the
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expression ((2 )-1). For example, if the burst tolerance calculated is 144, the actual burst tolerance
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used is 255 or ((2 )-1).
Burst tolerance is not applicable to the shaping of best-effort connections and the PCR-only
mode of shaping for VBR connections.
Hardware and Software Restrictions
ATM Switch Router Software Configuration Guide
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