AudioCodes MediaPack 114 Manual do Utilizador descarregar pdf (Página 326)

SIP User's Manual 326 Document #: LTRT-65411

MediaPack Series

When in VBD mode for V.152 implementation, support is negotiated between the device

and the remote endpoint at the establishment of the call. During this time, initial exchange

of call capabilities is exchanged in the outgoing SDP. These capabilities include whether

VBD is supported and associated RTP payload types ('gpmd' SDP attribute), supported

codecs, and packetization periods for all codec payload types ('ptime' SDP attribute). After

this initial negotiation, no Re-INVITE messages are necessary as both endpoints are

synchronized in terms of the other side's capabilities. If negotiation fails (i.e., no match was

achieved for any of the transport capabilities), fallback to existing logic occurs (according to

the parameter IsFaxUsed).

Below is an example of media descriptions of an SDP indicating support for V.152.

v=0

o=- 0 0 IN IPV4 <IPAdressA>

s=-

t=0 0

p=+1

c=IN IP4 <IPAddressA

m=audio <udpPort A> RTP/AVP 18 0

a=ptime:10

a=rtpmap:96 PCMU/8000

a=gpmd: 96 vbd=yes

In the example above, V.152 implementation is supported (using the dynamic payload type

96 and G.711 u-law as the VBD codec) as well as the voice codecs G.711 μ-law and

G.729.

Instead of using VBD transport mode, the V.152 implementation can use alternative relay

fax transport methods (e.g., fax relay over IP using T.38). The preferred V.152 transport

method is indicated by the SDP ‘pmft’ attribute. Omission of this attribute in the SDP

content means that VBD mode is the preferred transport mechanism for voice-band data.

To configure T.38 mode, use the CoderName parameter.

7.4 FXO Operating Modes

This section provides a description of the FXO operating modes and device configurations

for Tel-to-IP and IP-to-Tel calls.

7.4.1 IP-to-Telephone Calls

The FXO device provides the following operating modes for IP-to-Tel calls:

 One-stage dialing (refer to ''One-Stage Dialing'' on page 327)

• Waiting for di

al tone ''Two-Stage Dialing'' on page 328

• Time to wait before di

aling

• Answer supervision

 Two-stage dialing (refer to ''Two-Stage Dialing'' on page 328)

 Dialing time

• Disconnect supervision (refer to ''Call Termination (Disconnect Supervision) on

FXO Devices'' on page 328)

• DID wi

nk (refer to ''DID Wink'' on page 329)

1 2 ... 321 322 323 324 325 326 327 328 329 330 331 ... 389 390

Comentários a estes Manuais

Sem comentários

AudioCodes MediaPack 114 Manual do Utilizador Página 326

Comentários a estes Manuais

Manuais e produtos relacionados com Gateways/controladores AudioCodes MediaPack 114