Bandwidth requirements

Last Updated : Nov 24, 2014 |
For local branch calls involving Centralized users, the signaling path goes over the WAN to the Avaya Aura® Session Manager and back to the branch. These types of local branch call scenarios include:
  • Calls between two Centralized users in the same branch
  • Calls between a Centralized user and an IP Office user in the same branch
  • Calls between a Centralized user and the PSTN via a PSTN trunk on the local IP Office in the branch
While the signaling path goes over the WAN, the media path for such calls remains within the branch and does not go back and forth across the WAN. This depends on the central Avaya Aura® Communication Manager being appropriately configured for direct IP-IP audio.
  • If Avaya Aura® Communication Manager is configured for Initial Direct Media, then no media will be sent over the WAN for the call.
  • If Avaya Aura® Communication Manager is not configured for Initial Direct Media, but only for direct IP-IP audio or shuffling, then the first few media packets of each local call are relayed across the WAN through a Communication Manager central media resource, such as the G450 Media Gateway in the enterprise center. This occurs until Avaya Aura® Communication Manager shuffles the call so the media goes directly within the branch.

Exceptions for local calls

Exception cases where the media streams of local calls consume WAN bandwidth are as follows:
  • If the Centralized user initiates a conference on Avaya Aura® Communication Manager, then the different media streams are pulled by Communication Manager across the WAN to the central G4xx gateway. There is one media stream between the central G4xx gateway (where the Communication Manager conference is hosted) and each of the conference participants.
    For example, in a three-way sunny-day Communication Manager conference that includes two Centralized users in the branch and a PSTN caller through a local PSTN trunk on the IP Office in the branch, there will be three media streams across the WAN between the central G4xx gateway and the branch.
  • If the Centralized user puts the call on hold, then Avaya Aura® Communication Manager plays music-on-hold from the central G4xx gateway across the WAN to the branch.

Other call scenarios that consume WAN bandwidth

Calls between IP Office users and users in other sites of the enterprise are routed either through the Avaya Aura® Session Manager or through the PSTN, depending on how the solution is configured. If configured to route the calls across the SIP connection between the IP Office and the Avaya Aura® Session Manager, then both the signaling and the call media go across the WAN.
For site-to-site calls between Centralized SIP users in sunny-day, the signaling goes through the Avaya Aura® Session Manager and the media goes between the endpoints across the WAN. The IP Office in the branch is not involved in such calls. The Communication Manager Inter-Gateway Alternate Routing (IGAR) feature is not supported with IP Office branch deployments and the media flow of such site-to-site calls between Centralized SIP users cannot be sent through the PSTN instead of the WAN.