Cisco

Key QoS requirements and recommendations for interactive video (video conferencing) traffic:

• Interactive video traffic should be marked to DSCP AF41; excess video conferencing traffic can be marked down by a policer AF42 or AF43.
• Loss should be no more than 1 percent.
• One way latency should be no more than 150 ms.
• Jitter should be no more than 30 ms.
• Assign interactive video to either preferential queue or a second priority queue (when supported); when using Cisco IOS LLQ, overprovision the minimum priority bandwidth guarantee to the size of the video conferencing session plus 20 percent.

Key QoS requirements and recommendations for streaming video traffic:

• Streaming video should be marked to DSCP CS4, as designated by the QoS Baseline.
• Loss should be no more than 5 percent.
• Latency should be no more than 4 to 5 seconds (depending on the video application’s buffering capabilities).
• Guaranteed bandwidth (CBWFQ) requirements depend on the encoding format and rate of the video stream.
• Streaming video is typically unidirectional; therefore, remote branch routers might not require provisioning for streaming video traffic on their WAN or VPN edges (in the direction of branch to campus).
• Nonorganizational streaming video applications, such as entertainment video content, may be marked as scavenger (DSCP CS1), provisioned in the scavenger traffic class and assigned a minimal bandwidth (CBWFQ) percentage.

Reference

End-To-End QoS Network Design: Quality of Service in LANs, WANs, and VPNs

Disclosure

NetworkJutsu.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

Key QoS requirements and recommendations for call signaling traffic:

• Call signaling traffic should be marked as DSCP CS3 per the QoS Baseline (it can also be marked with the legacy value of DSCP AF31).
• 150 bps (plus Layer 2 overhead) per phone of guaranteed bandwidth is required for voice control traffic; more may be required, depending on the call signaling protocol.

References

Cisco QoS Exam Certification Guide (IP Telephony Self-Study) (2nd Edition)
End-to-End QoS Network Design: Quality of Service in LANs, WANs, and VPNs

Disclosure

NetworkJutsu.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

Key QoS requirements and recommendations for voice (bearer traffic):

• Voice traffic should be marked to DSCP EF per the QoS Baseline and RFC 3246.
• Loss should be no more  than 1 percent.
• One-way latency (mouth to ear) should be no more than 150 ms.
• Average one-way jitter should be targeted at less than 30 ms.
• A range of 21 to 320 Kbps of guaranteed priority bandwidth is required per call (depending on the sampling rate, the VoIP codec, and Layer 2 media overhead).

Reference

End-To-End QoS Network Design: Quality of Service in LANs, WANs, and VPNs

Disclosure

NetworkJutsu.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

There are three main components that make up the MQC (Modular QoS CLI) and are listed below:

• class-map – This is used as a classification filter defined within the policy map to identify traffic for preferential or deferential treatment. Traffic can be identified by IPP or DSCP, named or numbered ACL, Network-Based Application Recognition (NBAR), Layer 2 parameters (CoS, FR DE, ATM cell loss priority [CLP], MPLS Experimental [EXP] value), or combination of all of these.
• policy-map – This is used as a statement that defines how each traffic type, as identified by the class map(s), should be serviced. Options include marking/re-marking, policing, shaping, low-latency or class-based weighted fair queuing, selective dropping, and header compression.
• service-policy – This is used as a statement that binds the policy to an interface and specifies direction

For example:

ip access-list extended VOICE-RTP
 permit udp 192.168.1.0 0.0.0.255 any range 16384 32767
ip access-list extended VOICE-SIGNALING
 permit tcp 192.168.1.0 0.0.0.255 any range 2000 2002
!
class-map match-all VOICE-SIGNALING
 match access-group name VOICE-SIGNALING
class-map match-all VOICE-RTP
 match access-group name VOICE-RTP
!
policy-map VOICE
 class VOICE-RTP
 set dscp ef
 class VOICE-SIGNALING
 set dscp cs3
!
interface Vlan10
 description Voice VLAN
 service-policy input VOICE
!
end

References

Cisco QoS Exam Certification Guide (IP Telephony Self-Study) (2nd Edition)
End-to-End QoS Network Design: Quality of Service in LANs, WANs, and VPNs

Disclosure

NetworkJutsu.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

Cisco QoS tools fall into these categories:

• Classification and marking tools
• Policing and shaping tools
• Congestion-avoidance (selective dropping) tools
• Congestion-management (queuing) tools
• Link-specific tools

Click here for more information.

Disclosure

NetworkJutsu.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.