Cisco BPX 8650, Installation And Configuration Manual

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Cisco BPX 8600 Series Installation and Configuration
Release 9.3.30, Part Number 78-12907-01 Rev. E0, May 2005
Chapter 21 Configuring ATM Connections
ATM Connection Configuration
Use the dspcd command to determine if this feature is supported on a given slot.
Use the addcon command to set the minimum SCR and PCR values.
If these values are less than the minimum values supported on a given card, the command line interface
will not allow you to set them until you have disabled policing.
Note
A prompt lets you know about this limitation.
The cards supported by the minimum SCR and PCR values and their performance specifications are
listed in Table 21-11.
Note
The policing accuracy is always within 1%. The maximum SCR and PCR policing values are the
same as the line rate.
Policing must be disabled to support 6 cps minimum for all BXM card types.
Constant Bit Rate Connections
The CBR (constant bit rate) category is a fixed bandwidth class. CBR traffic is more time dependent,
less tolerant of delay, and generally more deterministic in bandwidth requirements.
CBR is used by connections that require a specific amount of bandwidth to be available continuously
throughout the duration of a connection. Voice, circuit emulation, and high-resolution video are typical
examples of traffic utilizing this type of connection.
A CBR connection is allowed to transmit cells at the peak rate, below the peak rate, or not at all. CBR
is characterized by peak cell rate (PCR).
The parameters for a CBR connection are shown in Figure 21-6 in the sequence in which they occur
during the execution of the
addcon command. The CBR policing definitions are summarized in
Table 21-12.
Table 21-11 Supported Cards and Performance Specifications
Card Name Card Types Minimum SCR and PCR, UPC/NPC Values
BPX-BXM T3/E3 12 cps
BPX-BXM OC3/STM-1 50 cps
BPX-BXM OC12/STM-4 50 cps