The Avaya IP Office platform is the ultimate in converged voice and data technology. IP Office brings a combination of voice and data applications formerly reserved for only the largest corporations. Cutting edge customer service with easy to use tools is now available to the smallest of businesses.
Implementation
A Control Unit plays the part of a Gateway between H.323 terminals and phones connected to the Control Unit (and also external lines). H.323 is configured on a Control Unit as a VPN line, specifying the IP address of a remote gateway and the audio compression to be used.
IP phones can be configured as extensions. An example is NetMeeting, which is configured to use the Control Unit as a Gatekeeper, with an account name that should match the name of a user configured on the Control Unit.
IP extensions are automatically created when an IP phone registers with the Gatekeeper (depending on a configuration option). If the user is not found a new user and extension are created, allowing the phone to be used immediately.
Basic call setup (without a Gatekeeper)
Call setup using H.225.0 encapsulated in Q.931 messages
Capability exchange using H.245
Establishment of audio communication using H.245 OpenLogicalChannel
Audio using RTP/RTCP
Fast connect procedure
Call setup using H.225.0 in Q.931 messages, with H.245 OpenLogicalChannel messages embedded in the H.225.0 messages
Audio using RTP/RTCP
Overlap sending
Support for overlap sending, where a SetupAck is sent in response to the Setup message
Gatekeeper
Gatekeeper support allows IP extensions to be automatically configured when they register with the gatekeeper.
Jitter buffer
5 frames of jitter buffer
Quality of Service
Layer3 - DiffServ TOS Field set to DSCP 6 on generated packets. WAN links optimize for this traffic when set to "PPPSyncVoice". At present normal LAN and normal ISDN traffic is not prioritized.
Layer4 - UDP Port Marking - all RTP/UDP traffic is sent within UDP port range of C000-CFFF (hex) (49152-53247)
