CIPT1 Cisco Voice over IP Volume Version 6.0 Student Guide Editorial, Production, and Web Services: 02.15.08 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study DISCLAIMER WARRANTY: THIS CONTENT IS BEING PROVIDED “AS IS.” CISCO MAKES AND YOU RECEIVE NO WARRANTIES IN CONNECTION WITH THE CONTENT PROVIDED HEREUNDER, EXPRESS, IMPLIED, STATUTORY OR IN ANY OTHER PROVISION OF THIS CONTENT OR COMMUNICATION BETWEEN CISCO AND YOU CISCO SPECIFICALLY DISCLAIMS ALL IMPLIED WARRANTIES, INCLUDING WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT AND FITNESS FOR A PARTICULAR PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE This learning product may contain early release content, and while Cisco believes it to be accurate, it falls subject to the disclaimer above The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study Students, this letter describes important course evaluation access information! Welcome to Cisco Systems Learning Through the Cisco Learning Partner Program, Cisco Systems is committed to bringing you the highest-quality training in the industry Cisco learning products are designed to advance your professional goals and give you the expertise you need to build and maintain strategic networks Cisco relies on customer feedback to guide business decisions; therefore, your valuable input will help shape future Cisco course curricula, products, and training offerings We would appreciate a few minutes of your time to complete a brief Cisco online course evaluation of your instructor and the course materials in this student kit On the final day of class, your instructor will provide you with a URL directing you to a short post-course evaluation If there is no Internet access in the classroom, please complete the evaluation within the next 48 hours or as soon as you can access the web On behalf of Cisco, thank you for choosing Cisco Learning Partners for your Internet technology training Sincerely, Cisco Systems Learning The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study Table of Contents Volume Course Introduction Overview Learner Skills and Knowledge Course Goal and Objectives Course Flow Additional References Cisco Glossary of Terms Your Training Curriculum Introduction to VoIP Overview Module Objectives Introducing VoIP Overview Objectives Cisco Unified Communications Architecture VoIP Essentials Business Case Components of a VoIP Network VoIP Functions VoIP Signaling Protocols H.323 Suite Media Gateway Control Protocol Session Initiation Protocol Skinny Call Control Protocol Comparing VoIP Signaling Protocols VoIP Service Considerations Media Transmission Protocols Real-Time Transport Protocol Real-Time Transport Control Protocol Compressed RTP Secure RTP Summary Lesson Self-Check Lesson Self-Check Answer Key Introducing Voice Gateways Overview Objectives Understanding Gateways Gateway Hardware Platforms Modern Enterprise Models Well-Known and Widely Used Enterprise Models Standalone Voice Gateways Summary of Voice Gateways IP Telephony Deployment Models Single-Site Deployment Design Characteristics Benefits of the Single-Site Model Single-Site Deployment: Design Guidelines Multisite WAN with Centralized Call Processing Design Characteristics Multisite WAN with Centralized Call Processing: Design Guidelines Multisite WAN with Distributed Call Processing Design Characteristics Benefits The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study 1 4 1-1 1-1 1-1 1-3 1-3 1-3 1-4 1-6 1-7 1-9 1-10 1-12 1-14 1-16 1-18 1-19 1-20 1-24 1-26 1-27 1-29 1-31 1-33 1-35 1-36 1-37 1-39 1-39 1-39 1-40 1-44 1-44 1-46 1-47 1-51 1-53 1-54 1-54 1-55 1-56 1-57 1-58 1-60 1-62 1-63 1-64 Multisite Distributed Call Processing: Design Guidelines Call-Processing Agents for the Distributed Call-Processing Model Clustering over the IP WAN Benefits WAN Considerations Summary Lesson Self-Check Lesson Self-Check Answer Key Specifying Requirements for VoIP Calls Overview Objectives IP Networking and Audio Clarity Jitter Delay Acceptable Delay Packet Loss Audio Quality Measurement Mean Opinion Score Perceptual Speech Quality Measurement Quality Measurement Comparison VoIP and QoS Objectives of QoS Using QoS to Improve Voice Quality Transporting Modulated Data over IP Networks Differences from Fax Transmission in the PSTN Fax Services over IP Networks Understanding Fax and Modem Pass-Through, Relay, and Store and Forward Fax Pass-Through Modem Pass-Through Fax Relay Modem Relay Store-and-Forward Fax Gateway Signaling Protocols and Fax and Modem Pass-Through and Relay Gateway-Controlled MGCP T.38 Fax Relay Call Agent-Controlled MGCP T.38 Fax Relay DTMF Support H.323 DTMF Support MGCP DTMF Support SIP DTMF Support Summary Lesson Self-Check Lesson Self-Check Answer Key Understanding Codecs, Codec Complexity, and DSP Functionality Overview Objectives Codecs Impact of Voice Samples and Packet Size on Bandwidth Encapsulated Bytes Calculation Example Calculating Overhead Data-Link Overhead IP Overhead VPN Overhead Example Calculating the Total Bandwidth for a VoIP Call Total Bandwidth Calculation Without VAD Example Effects of VAD on Bandwidth Digital Signal Processors Codec Complexity Configuring Codec Complexity Verifying Codec Complexity ii Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study 1-65 1-66 1-67 1-68 1-69 1-71 1-72 1-73 1-75 1-75 1-75 1-76 1-78 1-79 1-80 1-82 1-83 1-83 1-83 1-85 1-86 1-88 1-90 1-91 1-91 1-92 1-93 1-93 1-96 1-97 1-99 1-103 1-104 1-113 1-113 1-114 1-114 1-115 1-115 1-117 1-118 1-119 1-121 1-121 1-121 1-123 1-126 1-126 1-127 1-127 1-128 1-129 1-130 1-130 1-132 1-134 1-139 1-140 1-141 © 2008 Cisco Systems, Inc DSP Requirements for Media Resources Resource Allocation on the NM-HDV (C549-Based Hardware) Resource Allocation on the NM-HDV2, NM-HD-xx, and PVDM2 (C5510-Based Hardware) Configuring Conferencing and Transcoding on Voice Gateways DSP Farms DSP Profiles DSP Farm Configuration Commands for Enhanced Media Resources Verifying Media Resources Summary Lesson Self-Check Lesson Self-Check Answer Key Module Summary References Voice Port Configuration 1-142 1-142 1-142 1-153 1-155 1-156 1-157 1-161 1-163 1-164 1-166 1-167 1-167 2-1 Overview Module Objectives 2-1 2-1 Understanding Call Types 2-3 Overview Objectives Call Types Local Calls On-Net Calls Off-Net Calls PLAR Calls PBX-to-PBX Calls Intercluster Trunk Calls On-Net-to-Off-Net Calls Summary Lesson Self-Check Lesson Self-Check Answer Key 2-3 2-3 2-4 2-5 2-6 2-7 2-8 2-9 2-10 2-11 2-12 2-13 2-14 Configuring Analog Voice Ports 2-15 Overview Objectives Voice Ports Signaling Interfaces Analog Voice Ports FXS Interfaces FXO Interfaces E&M Interfaces Analog Signaling FXS and FXO Supervisory Signaling Analog Address Signaling Informational Signaling E&M Signaling Physical Interface E&M Address Signaling Configuring Analog Voice Ports When to Configure an FXS Port FXS Voice Port Configuration Example Trunks Analog Trunks FXO Port Configuration E&M Voice Port Configuration Centralized Automated Message Accounting Direct Inward Dialing Timers and Timing Configuration Verifying Voice Ports Summary © 2008 Cisco Systems, Inc 2-15 2-15 2-16 2-17 2-18 2-18 2-18 2-19 2-20 2-21 2-24 2-25 2-26 2-28 2-28 2-31 2-31 2-32 2-34 2-35 2-38 2-40 2-42 2-46 2-48 2-51 2-57 Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study iii Lesson Self-Check Lesson Self-Check Answer Key Understanding Dial Peers Overview Objectives Dial Peers and Call Legs End-to-End Calls Types of Dial Peers Dial-Peer Configuration Example Configuring POTS Dial Peers POTS Dial-Peer Configuration Practice Configuring VoIP Dial Peers VoIP Dial-Peer Configuration Practice Default Dial Peer Use of Default Dial Peer Example Configuring Destination-Pattern Options Matching Destination Patterns Example Matching Inbound Dial Peers Matching Outbound Dial Peers Matching Outbound Dial Peers Example Summary Lesson Self-Check Lesson Self-Check Answer Key Configuring Digital Voice Ports Overview Objectives Digital Voice Ports Digital Trunks T1 CAS E1 R2 CAS ISDN Overview BRI and PRI Interfaces ISDN Signaling ISDN Messages ISDN Information Element Cause Information Element Facility Information Element Progress Information Element Display Information Element Non-Facility Associated Signaling Configuring T1 CAS Trunks Framing Formats Line Coding Clock Sources Network Clock Timing DS0 Groups Configuring E1 R2 CAS Trunks Configuring ISDN Trunks Configuring a BRI Trunk Example Configuring PRI Trunks Example Verifying Digital Voice Ports Summary Lesson Self-Check Lesson Self-Check Answer Key iv 2-58 2-60 2-61 2-61 2-61 2-62 2-63 2-64 2-66 2-67 2-69 2-70 2-72 2-73 2-73 2-75 2-77 2-78 2-80 2-80 2-81 2-82 2-86 2-87 2-87 2-87 2-88 2-89 2-92 2-96 2-98 2-100 2-104 2-109 2-111 2-111 2-112 2-112 2-112 2-117 2-119 2-119 2-120 2-121 2-122 2-123 2-130 2-132 2-134 2-136 2-138 2-147 2-148 2-150 Understanding QSIG 2-151 Overview Objectives QSIG Overview 2-151 2-151 2-152 Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study © 2008 Cisco Systems, Inc QSIG Features Path Replacement Configuring QSIG Support Global QSIG Support Configuration Example Configuring QSIG over PRI Configuring QSIG over BRI Verifying QSIG Trunks debug isdn q921 debug isdn q931 Summary Lesson Self-Check Lesson Self-Check Answer Key Module Summary References © 2008 Cisco Systems, Inc 2-154 2-156 2-158 2-158 2-159 2-160 2-161 2-163 2-163 2-166 2-167 2-169 2-171 2-171 Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study v vi Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study © 2008 Cisco Systems, Inc Configuring QSIG Support This topic describes how to configure QSIG support on Cisco IOS gateways Configuring Global QSIG Support for BRI or PRI Example QSIG T1/E1 or BRI Channel QSIG T1/E1 or BRI Channel IP Network PBX Voice-Enabled Router Voice-Enabled Router PBX Phone BRI Router(config)# isdn switch-type basic-qsig PRI Router(config)# isdn switch-type primary-qsig Router(config)# card type t1 © 2008 Cisco Systems, Inc All rights reserved CVOICE v6.0—2-6 The diagram in the figure depicts a typical QSIG deployment topology Global QSIG Support Configuration Example In this example, you have been tasked to configure a T1 controller for a voice gateway according to this network requirement: Connection type = PRI, using timeslots to 24 Follow this procedure to configure global QSIG support for BRI or PRI 2-158 Step Configure the global ISDN switch type to support QSIG signaling Step Configure the digital signal processor (DSP) farm at the specified slot or port Step Specify the card type (T1 or E1) at the specified slot so that the router provides sufficient DSP resources Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study © 2008 Cisco Systems, Inc Configuring QSIG over PRI This subtopic describes how to configure QSIG over PRI QSIG over PRI Interface Configuration Example QSIG T1/E1 Channel QSIG T1/E1 Channel IP Network PBX Voice-Enabled Router Voice-Enabled Router PBX Phone Router(config)# controller t1 0/1 Router(config-controller)# pri-group timeslots 1-24 Router(config)# interface serial 0/1:23 Router(config-if)# isdn switch-type primary-qsig Router(config-if)# isdn protocol-emulate user OR Router(config-if)# isdn protocol-emulate network © 2008 Cisco Systems, Inc All rights reserved CVOICE v6.0—2-7 The example in the figure shows a PRI QSIG support configuration Follow this procedure to configure the T1 or E1 controller for QSIG over PRI Step Enter T1 or E1 controller configuration mode for the specified controller Step Specify PRI on the timeslots that make up the PRI group Separate low and high values with a hyphen Step Note Maximum T1 range: 1-24 Maximum E1 range: 1-31 Enter interface configuration mode for the specified PRI slot/port and D-channel ISDN interface D-channel ISDN interface is (for T1) 23 and (for E1) 15 Step If you did configure the global PRI ISDN switch type for QSIG support in global configuration mode, this command overrides that command and configures the interface ISDN switch type to support QSIG signaling Step (User side only) Configure Layer and Layer port mode emulation and clock status for the user, that is, the terminal equipment (clock slave) This is the default Or © 2008 Cisco Systems, Inc The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study Voice Port Configuration 2-159 (Network side only) Configure Layer and Layer port mode emulation and clock status for the network, that is, the Network Termination (NT) (clock master) Configuring QSIG over BRI This subtopic describes how to configure QSIG over BRI QSIG over BRI Configuration Example QSIG BRI Channel QSIG BRI Channel IP Network PBX Voice-Enabled Router Voice-Enabled Router PBX Phone Router(config)# interface bri 1/1 Router(config-if)# isdn layer1-emulate user OR Router(config-if)# isdn layer1-emulate network Router(config-if)# isdn incoming-voice voice Router(config-if)# isdn protocol-emulate user OR Router(config-if)# isdn protocol-emulate network © 2008 Cisco Systems, Inc All rights reserved CVOICE v6.0—2-8 Follow this procedure to configure QSIG support for BRI Step Enter BRI configuration mode for the specified BRI Step Configures Layer port mode emulation and clock status for the user, that is, the terminal equipment (clock slave) Step Enable routing of incoming voice calls Step (User side only) Configure Layer and Layer port mode emulation and clock status for the user, that is, the terminal equipment (clock slave) Or (Network side only) Configure Layer and Layer port mode emulation and clock status for the network, that is, the NT (clock master) 2-160 Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study © 2008 Cisco Systems, Inc Verifying QSIG Trunks This topic describes how to verify QSIG trunks Verifying Controllers router# show controllers t1 0/1/0 T1 0/1/0 is up Applique type is Channelized T1 Cablelength is long gain36 0db No alarms detected alarm-trigger is not set Soaking time: 3, Clearance time: 10 AIS State:Clear LOS State:Clear LOF State:Clear Version info Firmware: 20051006, FPGA: 20, spm_count = Framing is ESF, Line Code is B8ZS, Clock Source is Line CRC Threshold is 320 Reported from firmware is 320 Data in current interval (601 seconds elapsed): Line Code Violations, Path Code Violations 601 Slip Secs, Fr Loss Secs, Line Err Secs, Degraded Mins 601 Errored Secs, Bursty Err Secs, Severely Err Secs, Unavail Secs © 2008 Cisco Systems, Inc All rights reserved CVOICE v6.0—2-9 To display information about the PRI controller, use the show controllers command © 2008 Cisco Systems, Inc The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study Voice Port Configuration 2-161 ISDN Status router# show isdn status Global ISDN Switchtype = primary-qsig ISDN Serial0/1/1:23 interface dsl 0, interface ISDN Switchtype = primary-qsig **** Slave side configuration **** Layer Status: ACTIVE Layer Status: TEI = 0, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED Layer Status: Active Layer Call(s) Active dsl CCBs = The Free Channel Mask: 0x00000000 Number of L2 Discards = 0, L2 Session ID = Total Allocated ISDN CCBs = © 2008 Cisco Systems, Inc All rights reserved CVOICE v6.0—2-10 Use the show isdn status command to verify that the ISDN Layer is shown as ACTIVE and the Layer state is MULTIPLE_FRAME_ESTABLISHED If these conditions are satisfied, any problem that you encounter with the QSIG trunk is probably not with ISDN Layer or Layer 2, and troubleshooting should focus on ISDN Layer using the debug isdn q931 command If a TEI_UNASSIGNED or AWAITING_ESTABLISHMENT state is reported, verify the configuration For a back-to-back configuration, such as in a connection between a voice gateway and a PBX, one of the sides must be set to emulate the network Note 2-162 Remember, if network emulation is not correctly set, Layer will not come up Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study © 2008 Cisco Systems, Inc Debugging QSIG Trunks router# debug isdn q921 Displays ISDN Q.921 (Layer 2) debug information router# debug isdn q931 Displays information about call setup and teardown of Layer ISDN network connections between the local (user-side) router and the network © 2008 Cisco Systems, Inc All rights reserved CVOICE v6.0—2-11 There are a few commands that you can use to debug a QSIG trunk debug isdn q921 The debug isdn q921 command output is limited to commands and responses that are exchanged during peer-to-peer communication that is carried over the D channel This debug information does not include data that is transmitted over the B channels that are also part of the router ISDN interface The peers (data link layer entities and layer management entities on the routers) communicate with each other with an ISDN switch over the D channel Note The ISDN switch provides the network interface that is defined by Q.921 This debug command does not display data link layer access procedures taking place within the ISDN network (that is, procedures taking place on the network side of the ISDN connection) A router can be the calling or called party of the ISDN Q.921 data link layer access procedures If the router is the calling party, the command displays information about an outgoing call If the router is the called party, the command displays information about an incoming call and the keepalives You can use the debug isdn q921 command simultaneously with the debug isdn event, debug isdn q931, debug isdn q921 frame, and debug isdn q921 detail commands The displays are intermingled debug isdn q931 Use the debug isdn q931 command to watch the Q.931 signaling messages go back and forth while the router negotiates the ISDN connection © 2008 Cisco Systems, Inc The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed representations may not be used in commercial training, and may not be distributed for purposes other than individual self-study Voice Port Configuration 2-163 Debugging QSIG Trunks (Cont.) Q.931 on E1 European PRI router# show debugging The following ISDN debugs are enabled on all DSLs: debug isdn error is debug isdn event is debug isdn q931 is ON ON ON (filter is OFF) [ output omitted ] *Mar 13:25:20.698: ISDN Se0/2:15 Q931: Progress Ind i = 0x8088 - In-band 13:25:22.336: ISDN Se0/2:15 Q931: 13:25:22.344: ISDN Se0/2:15 Q931: *Mar *Mar 0x0004 *Mar 13:25:24.408: ISDN 0x8004 Cause i = 0x8090 *Mar 13:25:24.436: ISDN *Mar 13:25:24.468: ISDN 0x8004 RX [...]... Training Through Cisco Learning Partners CCIE Expert Quality of Service Cisco Voice over IP CCVP Professional CCNA Associate Troubleshooting Cisco Unified Communications Systems or Unified IP Telephony Troubleshooting Cisco IP Telephony Part 1 Cisco IP Telephony Part 2 CCVP www .cisco. com/go/certifications © 2008 Cisco Systems, Inc All rights reserved 6 Cisco Voice over IP (CVOICE) v6.0 The PDF files... gateways, only the IP address is available on Cisco Unified Communications Manager to confirm that communication between the Cisco Unified Communications Manager and the SIP voice gateway is possible 1- 18 Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files... skills to implement Cisco VoIP networks consisting of gateways and gatekeepers.” Cisco Voice over IP v6.0 © 2008 Cisco Systems, Inc All rights reserved CVOICE v6.0 4 Upon completing this course, you will be able to meet these objectives: 2 Describe VoIP, voice gateways, special requirements for VoIP calls, codecs and codec complexity, and how DSPs are used as media resources on a voice gateway Configure... references Cisco Icons and Symbols POTS Phone Voice Gateway IP Phone Switch IP Telephony Router with Cisco Unified Communications Manager Express Router Voice- Enabled Router PC Line: Serial Cisco Unified Communications Manager IP Cisco Unified Border Element PBX Network Cloud Line: Ethernet © 2008 Cisco Systems, Inc All rights reserved CVOICE v6.0 6 Cisco Glossary of Terms For additional information on Cisco. .. calls over an IP network VoIP services convert traditional TDM analog voice streams into a digital signal Call from: – Computer – IP Phone – Traditional (POTS) phone © 2008 Cisco Systems, Inc All rights reserved CVOICE v6.0 1- 3 VoIP is the family of technologies that allow IP networks to be used for voice applications such as telephony, voice instant messaging, and teleconferencing VoIP defines a... for an MGCP interaction to take place with Cisco Unified Communications Manager, the gateway must have Cisco Unified Communications Manager support If you are a registered customer of the Software Advisor, you can use this tool to make sure that your platform and your Cisco IOS software or Cisco Catalyst operating system 1- 16 Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation... 2008 Cisco Systems, Inc Lesson 1 Introducing VoIP Overview VoIP is also known as IP telephony or broadband telephony It routes voice conversations over IP- based networks including the Internet VoIP has made it possible for businesses to realize cost savings by utilizing their existing IP network to carry voice and data, especially where businesses have underutilized network capacity that can carry VoIP... responsible for the entire signaling between the Cisco Unified Communications Manager cluster and the gateway The ISDN protocols, Q.9 21 and Q.9 31, are used only on the ISDN link to the PSTN 1- 20 Cisco Voice over IP (CVOICE) v6.0 The PDF files and any printed representation for this material are the property of Cisco Systems, Inc., for the sole use by Cisco employees for personal study The files or printed... gateway control; thin device control SIP SCCP or “Skinny” IETF protocol for interactive and noninteractive conferencing; simpler, but less mature, than H.323 Cisco proprietary protocol used between Cisco Unified Communications Manager and Cisco VoIP phones © 2008 Cisco Systems, Inc All rights reserved CVOICE v6.0 1- 7 VoIP uses several control and call signaling protocols 1- 12 H.323: H.323 is a standard... multiple channels of communication as well as customer self-help tools Video telephony: Cisco Unified Video Advantage products enable real-time video communications and collaboration using the same IP network and call-processing agent as Cisco Unified Communications With Cisco Unified Video Advantage, making a video call is just as easy as dialing a phone number Cisco Voice over IP (CVOICE) v6.0