AudioCodes MediaPack MP-402, Руководство пользователя

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SIP User's Manual 1 . Overview
Version 2.4 15 June 2008
1.3
SIP Overview
SIP (Session Initialization Protocol) is an application-layer control (signaling) protocol used
on the MediaPack for creating, modifying, and terminating sessions with one or more
participants. These sessions can include Internet telephone calls, media announcements
and conferences.
SIP invitations are used to create sessions and carry Session Description Protocol (SDP)
messages that enable participants to agree on a set of compatible media types. SIP uses
elements called Proxy servers to help route requests to the user's current location,
authenticate and authorize users for services, implement provider call-routing policies and
provide features to users.
SIP also provides a registration function that enables users to upload their current locations
for use by Proxy servers. SIP, on the MediaPack, complies with the IETF (Internet
Engineering Task Force) RFC 3261 (refer to
288H298H
http://www.ietf.org ).
1.4
MediaPack Features
This section provides a high-level overview of some of the many MediaPack supported
features.
1.4.1 General Features
„
Superior, high quality Voice, Data, and Fax over IP networks
„
Toll quality voice compression
„
Proven integration with leading PBXs, IP-PBXs, Softswitches and SIP servers
„
Spans a range of 1 to 4 ISDN ports
„
Lifeline or Fallback assembly options
„
Configurable NT or TE support
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Point-to-Point or Point-to-Multipoint support
„
Selectable G.711 or multiple Low Bit Rate (LBR) coders per channel
„
T.38 fax with superior performance (handling a round-trip delay of up to nine seconds)
„
Echo Canceller, Jitter Buffer, Voice Activity Detection (VAD) and Comfort Noise
Generation (CNG) support
„
Comprehensive support for supplementary services
„
Web management for quick-and-easy configuration and maintenance
1.4.2 SIP Features
The MediaPack SIP gateway complies with the IETF RFC 3261 standard.
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Reliable User Datagram Protocol (UDP) transport, with retransmissions.
„
T.38 real time fax (using SIP).
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Works with Proxy or without Proxy, using an internal routing table.
„
Fallback to internal routing table if Proxy is not responding.