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with LLQ the entrance criteria to a class can be as granular as you like because you define it by an ACL. You are not limited, as with IP RTP priority, to a simple UDP port range. If the port range feature did not get changed

Voice QOS Design Considerations Notes:

General Considerations

• Do not use VoIP on a FR PVC that also carries VoFR
• Prioritize the PVC if it carries only voice traffic
• Don’t mark voice packets as DE
• Set IP Precedence = 5 on the dial peer
• Don’t use WRED for voice queues
• Turn on DTMF-relay for low bit-rate codecs (8k and below)
• Set echo, loss/gain parameters as specified by the network loss plan.
• Measure/calculate network packet delay – the goal is 150 to 200ms one-way.
• If TCP delays affect DTMF-relay performance use Cisco-rtp for DTMF-relay

Queuing Considerations

• LLQ – classify voice in a priority class
• Use ip rtp priority if LLQ is not available
• Set the bandwidth on the priority statement in the LLQ configuration (or in the ip rtp priority statement) to the aggregate number of calls per interface/PVC
• Create ACLs that prioritize both voice media and signaling

Fragmentation Considerations (speeds less than 1.5Mbps

• Fragment to a 10ms delay to optimize size for backbone packet/cell sizes and network delay characteristics
• Set fragments size so that voice packets are not fragmented
• Set the ppp multilink fragment-delay command on leased line interfaces
• Set the frame-relay fragment command in the FR map class
• Fragment all PVCs carrying data on the interface if at least one PVC carries voice

Traffic Shaping Considerations

• Set Be to 0
• Set Bc to 10ms (1/100 of CIR) for mixed voice/data PVCs
• Set mincir greater than or equal to bandwidth needed for voice
• Set FRTS on the interface
• Shape traffic strictly to the CIR on the PVC carrying voice
• Shape both sides of the VC to the slower link speed to prevent egress blocking

CAC Considerations

• Limit voice calls to prevent oversubscription of the bandwidth

Video QoS Design Considerations

• For bidirectional and/or low speed video use priority queuing and allocate 384Kbps for bandwidth
• For one-way video traffic use a CBWFQ mechanism

LLQ Considerations

• Large video MTUs placed in the LLQ’s priority queue with voice traffic will bypass the fragmentation engine and cause delays for the voice traffic.

CAC Considerations

• In a single-zone WAN model limit the number of video terminals
• In a multizone WAN model use Gatekeeper CAC. However, Gatekeeper CAC is only available in a hub-and-spoke network.