Filter
Top Products
Server Administration
78 4600 Series IP Telephone Release 2.2 LAN Administrator Guide
You can disable the Network Audio Quality data and assessment display for all sets by setting
the system value NTWKAUDIO to a value of “0.” Administering Options for the 4600 Series IP
Telephones on page 80 explains how to do so.
This information’s implication for LAN administration depends, of course, on the values the user
reports and the specific nature of your LAN, like topology, loading, QoS administration, etc. This
information’s major use is to give the user an idea of how network conditions affect the current
call’s audio quality. It is assumed you have more detailed tools available for troubleshooting the
LAN.
RSVP and RTCP
Avaya IP Telephones implement the Resource ReSerVation Protocol (RSVP) to support WAN
bandwidth management. RSVP is administered from the media server. Avaya IP Telephones
implement the RTP Control Protocol (RTCP) so Avaya’s Voice over IP (VoIP) Monitoring
Manager (VMON) software can provide real-time monitoring and historical data of audio quality
for VoIP calls.
Resource ReSerVation Protocol (RSVP) is an IETF-standard protocol hosts use to request
resource reservations throughout a network. RSVP-compliant hosts send messages through a
network to receivers. Receivers respond with messages requesting a type of service and an
amount of resources, for example, bandwidth, to carry out that service. The host is responsible
for admitting (approving) or rejecting (denying) the request. In a QoS context, RSVP tries to
reserve bandwidth on the network for voice calls on a call-by-call basis. If insufficient bandwidth
is available for the target voice quality, a request to use network bandwidth for a voice call is
rejected.
RTP Control Protocol (RTCP), as its name implies, is a protocol that provides control functions
for Real-time Transport Protocol (RTP). RTP provides end-to-end network services for real-time
data such as Voice over IP. But RTP does not provide a reservation function, nor does it
guarantee any level of QoS. RTCP supplements RTP by monitoring the quality of the RTP
services and can provide real-time information to users of an RTP service. In a QoS context,
RTCP is valuable to identify information such as:
● packet loss,
● 1-way delay or how long a packet has to go from source A to destination B,
● jitter, etc.
RTCP itself does not improve QoS, but provides information to help identify where problem
areas might be.
You cannot change the telephone’s RSVP or RTCP parameters directly on the telephone or by
TFTP or DHCP administration. The only way to change these parameters is by appropriate
switch administration. See your Avaya media server administration material for more detail.