Avaya 4600 Series manual Rsvp and Rtcp

	Server Administration
Parameter	Possible Values
Packet Loss	"No data" or a decimal percentage. Late and out-of-
	sequence packets are counted as lost, if they are
	discarded. Packets are not counted as lost until a
	subsequent packet is received and the loss confirmed by
	the RTP sequence number.
Packetization Delay	"No data" or an integer number of milliseconds. The
	number reflects the amount of delay in received audio
	packets, and includes any look-ahead delay associated
	with the codec.
One-way Network Delay	"No data" or an integer number of milliseconds. The
	number is one-half the value RTCP computes for the
	round-trip delay.
Network Jitter	An integer number of milliseconds reporting the average
Compensation Delay	delay introduced by the telephone’s jitter buffer.

In addition, based on the current values for the above parameters, the Network Audio Quality Screen presents the user with a qualitative assessment of the overall audio quality currently being experienced. This assessment is based on separate evaluations of the Packet Loss and the total Network Delay (the sum of Packetization Delay, One-way Network Delay, and Network Jitter Compensation Delay), and consideration of the codec in use.

The implication of this information for LAN administration depends, of course, on the values reported by the user and the specific nature of your LAN (topology, loading, QoS administration, etc.) The major use for this information is to give the user an idea of how network conditions are affecting the audio quality of the current call. It is assumed you have more detailed tools available for troubleshooting the LAN.

RSVP and RTCP

Resource ReSerVation Protocol (RSVP) is an IETF-standard protocol used by hosts to request resource reservations throughout a network. RSVP-compliant hosts send messages through a network to receivers, which respond with messages requesting a type of service and an amount of resources (e.g., bandwidth) to carry out that service. The host is responsible for admitting (approving) or rejecting (denying) the request. In a QoS context, RSVP is used to try to reserve bandwidth in 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 will be 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 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 for identifying information such as packet loss, 1-way delay (how long a packet has to go from source

QoS

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