Specifications

Performance Tuning, and Monitoring 161
this is by using the talk 5, error and interface commands. If input discards on
the voice adapters or missed frames on either the voice or FR interfaces are
detected, the number of receive buffers should be increased. Input and output
discards on the FR interfaces may be normal and acceptable if any of the FR
circuits are being overloaded with data, for example, attempting a large file
transfer while having four voice calls active.
5.1.8 Tuning Bandwidth Reservation System
It will be necessary to configure BRS on all interfaces that are supporting both
voice and data.
BRS will be used to control both the number of buffers that can be queued for a
given circuit and the priority given to the data that is being queued. The minimum
and maximum queue depths are configured per circuit at the BRS level, as shown
below:
These queue depths apply to each of the four queues in every traffic class that
BRS maintains. The minimum queue depth determines when BRS will discard
incoming frames when the input device is low on receive buffers. Being low on
input receive buffers means that the input device has x or fewer remaining buffers
available in which to receive data where x is equal to the low count as displayed
by the
talk 5 QUEUE command, shown below:
BRS will return the buffer to the input device if it is low on input buffers and if the
number of buffers in the queue to which the input frame would be added is
currently equal to or greater than the minimum queue depth. The maximum
queue depth determines the maximum number of buffers that will be queued in
the priority queue regardless of whether the input device is low on buffers. These
values should be increased along with the number of receive buffers per interface
when input discards are detected. Input discards are displayed per interface by
using the
talk 5, statistics command.
Config>FEATURE BRS
Bandwidth Reservation User Configuration
BRS Config>INTERFACE 0
BRS [i 0] Config>CIRCUIT
Circuit (PVC number or SVC name) to reserve bandwidth [16]?
BRS [i 0] [dlci 16]>QUEUE-LENGTH
BRS priority queue maximum length [10]?
BRS priority queue minimum length [3]?
BRS [i 0] [dlci 16]>
+QUEUE
Input Queue Output Queue
Net Interface Alloc Low Curr Fair Curr
0 FR/0 24 4 24 4 0
1 PPP/0 24 4 24 4 0
2 PPP/1 24 4 24 4 0
3 PPP/2 24 4 24 4 0
4 TKR/0 40 7 40 20 0
5 Voice/0 20 0 20 103 0
6 Voice/1 20 0 20 103 0
7 Voice/2 20 0 20 103 0
8 Voice/3 20 0 20 103 0
+