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Cisco AVVID Network Infrastructure Enterprise Quality of Service Design
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Chapter 3 QoS in an AVVID-Enabled Campus Network
Selecting an Access-Layer Switch
Example 3-5
Displaying QoS Detailed Statistics
cat6k-access> (enable) show qos stat 5/1
All packets dropped are in the 1st drop threshold of queue #1
Tx port type of port 5/1 : 2q2t
Q # Threshold #:Packets dropped
--- -----------------------------------------------
1 1:393210 pkts, 2:0 pkts
2 1:0 pkts, 2:0 pkts
Rx port type of port 5/1 : 1q4t
Q # Threshold #:Packets dropped
--- -----------------------------------------------
1 1:0 pkts, 2:0 pkts, 3:0 pkts, 4:0 pkts
Example 3-6
Displaying CoS-to-DSCP Mappings
cat6k-access> (enable) show qos map run cos-dscp-map
CoS - DSCP map:
CoS DSCP
--- ----
0 0
1 8
2 16
3
26
26 = AF31 Voice Control
4
34
34 = AF41 IP Video Conferencing
5
46
46 = EF Voice Bearer
6 48
7 56
Example 3-7
Displaying IP Precedence-to-DSCP Mappings
cat6k-access> (enable) show qos map run ipprec-dscp-map
IP-Precedence - DSCP map:
IP-Prec DSCP
------- ----
0 0
1 8
2 16
3
26
26 = AF31 Voice Control
4
34
34 = AF41 IP Video Conferencing
5
46
46 = EF Voice Bearer
6 48
7 56
Catalyst 4000 as an Access-Layer Switch
Another popular campus configuration for Cisco AVVID networks uses the Catalyst 2948G, the Catalyst
2980G, and the Catalyst 4000 family of switches in the wiring closets.
There are several compelling reasons for this, including:
·
The Catalyst 4006 can provide in-line power to the IP phones.
·
The Catalyst 4000 offers a very low price per port.
·
These switches provide extremely scalable, high-speed switching.
Starting with Catalyst OS Release 5.2, the Catalyst 4000 switches support dual-transmit queues on every
interface. Admission to the queues is based on Layer 2 CoS markings and is configurable in 802.1p user
priority pairs.