Product Description
IP Office 8.1
© 2012 AVAYA All rights reserved.
Page 274
Issue 26.k.- (16 August 2012)
Compression
G.723.1 (6.3K)
G.729a (8K)
G.711 (64K)
Algorithmic Delay
(seconds)
0.08
0.04
0.02
Number of Calls
- 64Kbps Link
6
4
0
- 128Kbps Link
12
9
1
- 256Kbps Link
25
19
3
- 512Kbps Link
51
38
7
- 1Mbps Link
103
77
14
- 2Mbps Link
207
155
29
What is the Maximum Number of Simultaneous VoIP Calls
Each IP Office can be fitted with optional Voice Compression Modules (VCM) to support VoIP connections.
The IP500 V2 is capable of supporting two VCM 32/64 modules allowing up to 128 simultaneous calls. With
combination cards, another 10 VCMs are provided per card. Up to two combination cards are supported with IP
Office.
Network Assessment
With IP Office, optimum network configurations can support VoIP with a perceived voice quality equivalent to
that of the Public Switched Telephone Network (PSTN). However, not every network is able to take advantage
of VoIP transmissions. It is important to distinguish between basic compliance with the minimal VoIP standards
and validated support for QoS which is needed to run VoIP applications over a data network.
With the exception of standalone configurations where IP telephones connect directly connected to the ports on
IP Office, Avaya now requires that all customers formally audit their networks for IP telephony readiness before
attempting to install any VoIP application.
A network assessment should normally include:
·
Physical inventory of all equipment inclusive of the current version of code, and configurations as
needed.
·
An accurate and complete network topology for all networked sites, inclusive of IP addressing and
physical/logical connections.
·
An evaluation of the network's topology to check that the design is both sound and reasonable.
·
Measurement of packet loss, jitter and delay over the course of multiple days and measured on a per
minute basis. A graphical representation of the data is the preferred output method.
·
Examination of QoS/Class of Service (CoS) parameters in place in the network.
·
Summary of findings and possible actions to correct problems.
The assessment should leave you confident that the implemented network will have the capacity for the
foreseen data and voice traffic, and can support H.323, DHCP, TFTP, and jitter buffers in H.323 applications.
With this in mind, if you require support during or after an IP Office VoIP installation, a copy of your network
assessment documentation will be requested by your support channel.
For more details about available tools, resources and services to enable you to audit your network for VoIP
readiness, please contact your local Avaya representative.
IP Packet Flow Control
While a high-performance switch forwards data packets at full wire speed to and from its ports simultaneously,
there may be times when a switch port may not be able to accept packets at the rate it is receiving them.
For example, the switch port may be receiving packets from multiple ports at the same time, or the switch port
may be receiving packets from a port operating at a faster speed. For instance, the sending port might be
operating at 100 Mbps, while the receiving port operates at 10 Mbps; or the sending port might operate at
1000 Mbps, while the receiving port operates at 100 or 10 Mbps. If data packets arrive for a port that is
saturated with other packets, the packets may overflow the port’s buffer, resulting in dropped packets and lost
data.
Flow control is a congestion-control mechanism that prevents data loss at congested ports. Flow control
prevents packet loss by controlling the flow of data from the transmitting device to ensure that the receiving
device can handle all of the incoming data.
