© 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v5.01-1 Enable IP Video Telephony Introducing IP Video Telephony. - презентация

1 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Enable IP Video Telephony Introducing IP Video Telephony

2 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Cisco IP Video Telephony Solution IP

3 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v IP Video Telephony Solution Components Cisco Unified CallManager: –Providing single dial plan and call control –Managing video resources –Supporting H.323, SIP, and SCCP video devices Cisco Unified videoconferencing 3500 Series video gateways and MCUs: –Enables ad hoc conferencing for video devices –Acts as a gateway for H.320 or H.323 video calls –Configurable as H.323, SCCP, or H.323 and SCCP Cisco Unified Video Advantage: –H.263-compliant –Interoperates with H.323 and SIP –Requires Cisco Unified IP Phone 7941, 7940, 7961, 7960, 7971, or 7970 or Cisco IP Communicator 2.0 Video endpoints (SCCP): –Tandberg (emulates Cisco Unified IP Phone 7960) –Cisco Unified IP Phone 7985 H.323 and SIP endpoints: –Available from partners

4 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Video-Enabled IP Telephony: The Big Picture Cisco Unified CallManager Cluster H.320 Room System H.323/ SCCP MCU H.323- H.320 Gateway Gatekeeper/ Gateway H.323 Room System Phone + Video Video POTS Video TANDBERG MXP 150 Cisco Unified IP Phone 7985 PSTN or ISDN IP WAN

5 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Video Calls Video call is like a telephone call: Unified voice and video dial plans Calls can be made to SIP, H.323, or SCCP video and audio terminals Automatic codec, format, and bit-rate negotiation Single directory number for voice and video

6 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Cisco Unified CallManager Video Calls A video call is between two video-enabled endpoints. A videoconference is between more than two video-enabled endpoints. Video Call Setup Voice RTP Stream Video RTP Stream User B DN :4567 User A DN :1234

7 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Cisco Unified CallManager Video Call Flow Audio + Video Capabilities Request Call Answer Call Audio Capability Negotiation Audio Streaming Video Capability Negotiation Video Streaming Audio + Video Capabilities

8 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Cisco Unified CallManager Supported Video Codecs CodecStandard codecs: H.261, H.263+, H.264 Cisco proprietary codec: Cisco Wideband Supported Video Call Speed 128–1544 kbps7 Mbps ResolutionCIF, QCIF, 4CIF, 16CIF, SQCIF CIF Frame Rate15–30 fps

9 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v PSTN Video Protocols Supported in Cisco Unified CallManager SCCP Video Gatekeeper H.323 or SIP Video

10 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v SCCP and H.323 Endpoint Characteristics SCCP ClientsH.323 Clients Register with Cisco Unified CallManager Register with H.323 gatekeeper Send dialed number digit by digitSend entire dialed number at once Are configured in Cisco Unified CallManager Administration Are configured through user interface Advertise their capabilities when registering Advertise their capabilities on a call-by-call basis Offer PBX-style featuresOffer basic call capabilities in interaction with Cisco Unified CallManager

11 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v SCCP Video Call Characteristics SCCP video devices report video capabilities to Cisco Unified CallManager. Cisco Unified CallManager system administration determines video call bandwidth control. Cisco Unified CallManager supports H.261, H.263+, H.264 and Cisco wideband video codec. Cisco Unified CallManager supports G.711, G.723.1, G.728, G.729, G.722, Cisco wideband audio codec, and GSM. Cisco Unified CallManager uses out-of-band dual-tone multifrequency (DTMF).

12 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v H.323 Video Call Characteristics Call forwarding, dial plan, and other call routing-related features work with H.323 endpoints. H.323 video endpoints can be configured as H.323 phones, H.323 gateways, or H.323 trunks. Trunk interaction with H.323 clients has functions that are identical for audio and video calls. Neither video MTPs nor video transcoders exist currently.

13 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v H.323 Video Call Characteristics (Cont.) H.323 video endpoints cannot initiate hold, resume, transfer, park, and other, similar features. If an H.323 device supports ECS, the device can be set on hold, park, and so on. Cisco Unified CallManager supports H.323 dynamic E.164 alias addressing. Cisco Unified CallManager supports H.261 and H.263. H.323 video clients support G.711, G.723.1, G.728, G.729, and G.722. FECC is supported. Cisco Unified CallManager uses out-of-band DTMF (H.245 alphanumeric).

14 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v SCCP vs. H.323 in Cisco Unified CallManager The features supported in a video call may depend on the signaling protocol used. SCCPH.323 Call Features (Hold, Park, Transfer) YesYes (only passive, with H.323 endpoints supporting ECS) VideoconferenceMCU required H.320 InterworkingH.323 video gateway required FECCYes DTMFYes (out-of-band)Yes Mid-Call VideoYesYes (only if H.323 supports request in active call)

15 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Bandwidth Management Bandwidth management is important in the packet-switched network to ensure the quality of each voice and video call. Bandwidth calculation considerations: –Video call speed is the sum of the audio and video channels. –Video call bandwidth consists of video call speed and packetization overheadthe actual bandwidth required on the link.

16 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Video Call Bandwidth Requirement Video call includes two channels: –Audio channel –Video channel The bit rate available for the video channel depends on the negotiated audio codec and the overall video call speed. 320 kbps 376 kbps Video Call Speed at 384 kbps with G.711 Video Call Speed at 384 kbps with G kbps 8 kbps AudioVideo

17 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Calculating the Total Bandwidth To calculate the total bandwidth of a video call, including Layer 3 and Layer 2 overhead, add about 20 percent to the speed of the video call. Video Call Speed Bandwidth Required 128 kbps153 kbps 384 kbps460 kbps 512 kbps614 kbps 768 kbps921 kbps 1.5 Mbps1.8 Mbps kbps IP Overhead Audio 384 Video

18 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Call Admission Control Settings in Cisco Unified CallManager Cisco Unified CallManager Region Cisco Unified CallManager Location H.323 Gatekeeper Audio-Only Call Configuration Audio codec only Audio codec bit rate + Layer 3 overhead Twice the audio codec bit rate Example: G.711 Call G kbps128 kbps Video Call Configuration Audio codec and video call speed Video call speedTwice the video call speed Example: 384- kbps Video Call G.711 and 384 kbps 384 kbps768 kbps

19 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Call Admission Control Within a Cluster Is there enough bandwidth available for a good-quality video call?

20 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Call Admission Control Within a Cluster (Cont.) Regions –The Cisco Unified CallManager region specifies the maximum bandwidth used by a call: Between Cisco Unified CallManager regions Within a Cisco Unified CallManager region Locations –The location defines the maximum bandwidth to and from a location. –The number of permitted calls depends on the settings of the region (bandwidth per call). RSVP-enabled locations –RSVP agents are used for CAC between locations. –RSVP agents are Cisco IOS routers that use pass-through MTPs. Bandwidth to a certain location Codec properties define volume of calls to a location.

21 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Regions Audio Codec: –Specifies the audio codec with the highest allowed codec bit rate –Applies to audio channels of audio and video calls Video Call Bandwidth: –Specifies the maximum video call speed (without overhead) For video calls between different vendors, G.711 might be the only common audio codec. Affects which audio codec is used for video calls as well

22 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Locations Audio bandwidth settings apply to audio-only calls only, not to the audio channel of a video call. Video bandwidth setting applies to video calls only: –Bit rate is video call speed (audio and video channel). For RSVP-enabled locations, there are three possible modes: Optional (Video Desired), Mandatory, and Mandatory (Video Desired). Optional (Video Desired): Video call is set up as audio-only call if RSVP for video channel fails (even if RSVP also fails for the audio channel). Mandatory: Video call fails if RSVP is not successful for both channels. Mandatory (Video Desired): Video call is set up as audio-only call if RSVP for video channel fails and RSVP is successful for the audio channel.

23 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Video Call Bandwidth Example: Locations San FranciscoDallas Audio Bandwidth96 kbps640 kbps Video Bandwidth384 kbps768 kbps San Jose Four G.729 Voice Calls One 384-kbps Video Call One Mbps Circuit Eight G.711 Voice Calls Two 384-kbps Video Calls Two Mbps Circuits 1 Dallas X 2 San Francisco

24 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Retry Video Call as Audio When Cisco Unified CallManager detects insufficient bandwidth for a video call, it can retry the call as audio only. Retry Video Call as Audio is configurable on: –Cisco Unified IP Phone 7941, 7961, 7960, 7971, and 7970 –H.323 devices –H.323 gateways Gatekeeper-controlled trunks –H.225 trunks –SIP trunks

25 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Video Call Bandwidth Example: Retry Video Call as Audio Retry Video Call as Audio Enabled -> Audio Connection Established San FranciscoDallas Audio Bandwidth96 kbps640 kbps Video Bandwidth384 kbps768 kbps San Jose Four G.729 Voice Calls One 384-kbps Video Call One Mbps Circuit Eight G.711 Voice Calls Two 384-kbps Video Calls Two Mbps Circuits 1 Dallas X 2 San Francisco 3

26 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Call Admission Control Between Clusters CAC on nongatekeeper- controlled intercluster trunks or SIP trunks: –Locations and regions CAC on gatekeeper- controlled intercluster trunk: –Gatekeeper CAC –Locations and regions CAC to other Cisco Unified CallManager clusters or other H.323 systems with H.225 gatekeeper trunks: –Gatekeeper CAC –Locations and regions Gatekeeper

27 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Gatekeeper Call Admission Control Options Gatekeeper CAC is based on zones: –Local and remote zones Different options to limit the bandwidth: –Interzone, remote, total, session Zone C Zone A Zone B Remote, Interzone Total, Session Interzone Gatekeeper

28 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Gatekeeper Call Admission Control Example cluster zone local cluster-1 domain.com zone local cluster-2 domain.com zone prefix cluster zone prefix cluster bandwidth interzone cluster bandwidth session cluster bandwidth interzone cluster bandwidth session cluster Gatekeeper cluster-2

29 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v Summary The Cisco video telephony solution supports SCCP and H.323 devices. For videoconferences, an MCU is required. The typical video call includes two or three RTP streams in each direction. SCCP clients offer PBX features, and H.323 clients support basic call functionality. For the needed bandwidth, add 20 percent to the speed of the video call. CAC within a cluster is done through Cisco Unified CallManager locations and regions. CAC between clusters is done through gatekeeper control.

30 © 2006 Cisco Systems, Inc. All rights reserved.CIPT2 v