sábado, 19 de maio de 2007

Protocolos VOIP Standards.

Signalling

ITU-T Standards and Recommendations

H.323 V2

Packet-based multimedia communications systems

H.225.0

Call signalling protocols and media stream packetization for packet-based multimedia (includes Q.931 and RAS)

H.225.0 Annex G

Gatekeeper to gatekeeper (inter-domain) communications

H.245

Control protocol for multimedia communications

H.235

Security and encryption for H-series multimedia terminals

H.450.x

Supplementary services for multimedia:
1. Generic functional protocol for the support of supplementary services in H.323
2. Call transfer
3. Diversion
4. Hold
5. Park & pickup
6. Call waiting
7. Message waiting indication

H.323 Annex D

Real-time fax using T.38

H.323 Annex E

Call connection over UDP

H.323 Annex F

Single-use device

T.38

Procedures for real-time group 3 facsimile communications over IP networks

T.120 series

Data protocols for multimendia conferencing

IETF RFCs and Drafts

RFC 2543

SIP: Session initiation protocol

RFC 2327

SDP: Session description protocol

Internet Draft

SAP: Session announcement protocol

Gateway Control

ITU

H.GCP

Proposed recommendations for gateway control protocol

IETF

Internet Draft

MGCP: Media gateway control protocol

Internet Draft

MEGACO protocol

Draft

SGCP: Simple gateway control protocol

Internet Draft

IPDC: IP device control

Media Transport

IETF

RFC 1889

RTP: Real-time transport protocol

RFC 1889

RTCP: Real-time transport control protocol

RFC 2326

RTSP: Real-time streaming protocol

Media Encoding

ITU

Voice

Standard

Algorithm

Bit Rate (Kbit/s)

Typical end-to-
end delay (ms)
(excluding
channel delay)

Resultant Voice Quality

G.711

PCM

48, 56, 64

<<1

Excellent

G.723.1

MPE/ACELP

5.3, 6.3

67-97

Good(6.3), Fair(5.3)

H.728

LD-CELP

16

<<2

Good

G.729

CS-ACELP

8

25-35

Good

G.729
annex A

CS-ACELP

8

25-35

Good

G.722

Sub-band ADPCM

48, 56, 64

<<2

Good

G.726

ADPCM

16,24,32,40

60

Good(40), Fair(24)

G.727

AEDPCM

16, 24, 32, 40

60

Good(40), Fair (24)

Video

Standard

Algorithm

Bit Rate (Kbit/s)

Picture Quality

H.261

Discrete cosine transform (DCT) with motion compensation

px64 (p=# of ISDN B channels)

Low

H.263

Improved version of H.261

Various

Medium


Nenhum comentário:

Ads Inside PostM

Teste