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Cisco AVVID Network Infrastructure Enterprise Quality of Service Design
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Chapter 4 QoS in an AVVID-Enabled Wide-Area Network
QoS Recommendations for WAN Aggregation Routers
The following design principles apply when determining bandwidth provisioning requirements for
combining voice, video and data over a single WAN link:
·
Video requires 460 kbps of LLQ for each 384 kbps stream.
·
VoIP also requires LLQ bandwidth (depending on number of phones, CODECs etc.).
·
Total LLQ provisioning is recommended to be less than or equal to 33% of the link-capacity.
Although the ratios of voice and video may vary from one enterprise to another, if they are roughly the
same then a minimum bandwidth recommendation for combined voice, video and data would be 3 Mbps.
To meet this design recommendation in a point-to-point topology, two T1 links have been combined into
a MLP bundle and the MQC policy is applied to the multilink Interface.
Example 4-18 Combined Voice, Video and Data over Point-to-Point Links
interface Multilink 40
bandwidth 3072
ip address 10.200.40.1 255.255.255.252
service-policy output WAN-EDGE
ppp multilink
multilink-group 40
!
...
!
interface Serial1/0
description Link T1-A to BRANCH#40
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
multilink-group 40
!
interface Serial1/1
description Link T1-B to BRANCH#40
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
multilink-group 40
Example 4-19 Combined Voice, Video and Data over Frame-Relay Links
interface Serial0/1
description Parent FR Link
no ip address
encapsulation frame-relay
!
interface Serial0/1.50 point-to-point
description FR Link to BRANCH#50
bandwidth 3000
ip address 10.200.50.1 255.255.255.252
frame-relay interface-dlci 211
class REMOTE-BRANCH-3000kbps
This command applies the FRTS map-class to the DLCI.
!
...
map-class frame-relay REMOTE-BRANCH-3000kbps
frame-relay cir 3000000
frame-relay bc 30000
frame-relay be 0
frame-relay mincir 3000000
no frame-relay adaptive-shaping
service-policy output WAN-EDGE
This command applies the MQC policy to the FRTS map-class.