Mediant 2000 SIP User’s Manual

8. Gateway Capabilities Description

8.6.4Relevant Parameters

The following parameters (described in Table 6-5) are used to configure the Alternative Routing mechanism:

AltRoutingTel2IPEnable

AltRoutingTel2IPMode

IPConnQoSMaxAllowedPL

IPConnQoSMaxAllowedDelay

8.7Working with Supplementary Services

The Mediant 2000 SIP gateway supports the following supplementary services:

Hold / Retrieve

Transfer

Call Forward (doesn't initiate call forward, only responds to call forward request)

Call Waiting

Mediant 2000 SIP users are only required to enable the Hold and Transfer features. The call forward (supporting 30x redirecting responses) and call waiting (receive of 182 response) features are enabled by default. Note that all call participants must support the specific used method.

Note: When working with application servers (such as BroadSoft’s BroadWorks) in client server mode (the application server controls all supplementary services and keypad features by itself), the gateway’s supplementary services must be disabled.

8.7.1Call Hold and Retrieve Features

The party that initiates the hold is called the holding party, the other party is called the held party. The Mediant 2000 can't initiate the hold, but it can respond to hold request, and as such it is a held party.

After a successful hold, the held party should hear HELD_TONE, defined in gateway's Call Progress Tones file.

Retrieve can be performed only by the holding party while the call is held and active.

After a successful retrieve the voice should be connected again.

The hold and retrieve functionalities are implemented by Reinvite messages. The IP address 0.0.0.0 as the connection IP address or the string “a=inactive” in the received Reinvite SDP cause the gateway to enter Hold state and to play held tone (configured in the gateway) to the PBX/PSTN. If the string “a=recvonly” is received in the SDP message, the gateway stops sending RTP packets, but continues to listen to the incoming RTP packets. Usually, the remote party plays, in this scenario, Music on-hold (MOH) and the Mediant 2000 forwards the MOH to the held party.

8.7.2Call Transfer

There are two types of call transfers:

Consultation Transfer

Blind Transfer

The common way to perform a consultation transfer is as follows:

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Nortel Networks TP-1610 SIP Working with Supplementary Services, Relevant Parameters, Call Hold and Retrieve Features