Avaya 38DHB0002UKDD - Manual (Page 97)

How Do I? Part 2 Voice Over IP - Page 97
Step 3 - Configure IP Connectivity
Configure the IPNC for the appropriate IP connectivity option.
IP Connectivity Options
LAN 10/100 Ethernet
The IPNC transmitted VoIP packets to LAN are distinguish with the TOS field
setting. In this case it would be the function of other systems on the LAN to
ensure that voice traffic is protected from delay.
Lease line (PPP)
Avaya QoS for Slow Speed WAN links ensure that non-voice traffic does not
adversely affect the delay sensitive VoIP stream. The Avaya QoS can also be
configured to interoperate with a 3rd party router over a WAN link.
Frame Relay
Using Frame Relay with PPP encapsulation it is possible to provide VoIP over
Frame Relay between two INDeX systems.
Digital services
The term Digital service to refers to QSIG, DPNSS ISDN-ePRI, ISDN-2e. The
IPNC can be configured to provide VoIP over single or multiple (bundled) bearer
channels. A single ISDN bearer channel, for example, can be used to support up
to 5 concurrent VoIP calls. The bandwidth of a G711 VoIP call is equal to the
bandwidth of a single bearer channel. Hence G711 compression is not supported
for this connectivity type.
QoS
Operation
The diagram below illustrates the operation of Avaya’s IPNC QoS mechanism for
slow speed WAN links.
Router IP Header
Compression
Interface Multilink
Fragmentation
PPP Link
Signalling
Non-Voice
Header
Comp.
Multilink
Voice
Traffic &
Signalling
Normal
Compressed
V3
Voice
V2 V1
D1
Non-Voice
VPN Line
D1-2 V2 D1-1 V1
Voice packets are transmitted with a fixed length and intervals (1x20ms) and
must not be delayed through the interface.
The illustration shows voice packets (V1, V2 and V3) and non-voice packet D1
arriving at the PPP interface. The non-voice packet D1 is made to fit into the
interval between successive voice packets. This is accomplished by processing
large non-voice packets through PPP Multilink. The Multilink process “fragments”
the larger non-voice packet (D1) into smaller components (D1-1 and D1-2) for
serialization to the PPP link. Voice packets are not fragmented in this way. Layer
3 (call control) packets are fragmented and inserted when bandwidth is available
in the same way as non-voice packets.
INDeX IPNC Cassette Administration Manual How Do I? - Page 97
38DHB0002UKDD – Issue 7 (22/11/02) Part 2 Voice Over IP