Avaya IP Telephony User Manual download pdf (Page 78)

KW Avaya IP Telephony Implementation Guide

Appendix H: IPSI Signaling Bandwidth Requirements

VoIP deployments require the provisioning of priority service for VoIP bearer traffic (RTP) and a

guaranteed bandwidth service for Call Signaling. General VoIP requirements are discussed in the

AVAYA IP Voice Quality Network Requirements document available on the www.support.avaya.com

website. The following list summarizes key QoS requirements for voice traffic.

• Voice bearer traffic should be marked with DSCP 46 (EF).

• Voice bearer and Voice Signaling Packet loss should not be greater than 3%.

• One-way delay should be no more than 150 milliseconds.

• Average one-way jitter should be less than 30 milliseconds.

• H.323 Signaling Traffic should be marked DSCP 26 (AF31)

• IPSI Call signaling traffic should be given a guaranteed bandwidth on WAN links.

• IPSI Signaling Packet loss should not be greater than 3%.

The IPSI circuit pack provides enterprises with the capability to IP-connect Port Networks over

LAN/WAN links in simplex and high availability configurations. Call signaling and system maintenance

traffic is passed between S87XX/S8500 call control servers and the IPSI circuit packs in a port network.

The call signaling traffic is encapsulated AVAYA proprietary CCMS (Control Channel Message Set)

messages inside TCP/IP packets. The CCMS messages are H.323, H.225, and Q.931 messages used for

registration of IP endpoints, to setup and teardown calls, periodic testing of the hardware, and keep-alive

messages for IPSI connected port networks. These CCMS messages are critical to the stability of a port

network and delivery of CCMS messages must be guaranteed.

The following table and graph displays IPSI call signaling traffic for varying Busy Hour Call Completion

rates (BHCC). BHCC IPSI bandwidth is based on 150 IP endpoints originating and answering 10 second

duration ISDN trunk calls within a port network. The simulated call scenario is a general business case.

The common defaults for station traffic usage in a general business scenario are light traffic, moderate

traffic, and heavy traffic.

BHCC

Per PN

Usage Per Station

IPSI Bandwidth (Kbps)

full duplex

IPSI TCP/IP packets

per second

1K Light Traffic 17.3 21

2.5K 30.5 37

5K Moderate Traffic 52.2 61

7.5K 73.8 85

10K Heavy Traffic 83.5 107

1 2 ... 73 74 75 76 77 78 79 80 81

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Avaya IP Telephony User Manual Page 78