Troubleshooting Cisco CallManager, Network Signaling and Dial Plan © 2004 Cisco Systems, Inc. All rights reserved. Troubleshooting Cisco CallManager Signaling Architecture IPTT v4.02-1

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Troubleshooting Cisco CallManager Signaling Architecture: Objectives Upon completing this lesson, you will be able to: Describe CCM Architecture Explain H.323 protocol functionality Explain session initiation protocol (SIP) functionality Explain Q.931 protocol functionality Identify call flow traces within CCM Describe MGCP call setup Describe call preservation methods Apply CCM troubleshooting methods for problem solving utilizing the web-based trace tool

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Outline Overview CallManager Signaling Overview H.323 Protocol Overview MGCP Protocol Functionality Session Initiation Protocol Architecture ISDN and Q.931 Station Definition and Call Flow Call Preservation Cisco CallManager Trace and Cisco Trace Collection Tool Summary Quiz

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v MGCP or H.323 GatewayIP Phone SCCP CM2 RTP CM1 IP Phone SDL Cisco CallManager Signaling

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v H.323 Protocol Application Presentation Session Transport Data Link Physical Network Audio Signal G.711 G.722 G G.728 G.729 Video Signal H.261H.263 T.127 Data T.126 RTCP H.235 UDP RASRTP T.124 T.125/T.122 Supplementary Services H.450.3H H Control H.245H.225 TCP X RTCP = RTP Control Protocol

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v H.323 Interface Architecture H.323 Interface H.225Cdpc (Per Call) H.323 Device Call Control H.245 Interface (Per Connection) H.225Init H.225D (Per Station)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Gatekeeper-Controlled H.323 Calls BA Gatekeeper H.323 RAS Registered Cisco CallManager AB H.323 Version 2 ARQ ACF Skinny RTP

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v RAS H.225 H.245 RAS (ARQ) RAS (ACF) H.225 SETUP H.225 Call Proceeding RAS (ARQ) RAS (ACF) H.225 Alerting Connection (H.245 Address) Terminal Capability Set + Acknowledgment Master-Slave Determination Terminal Capability Set – Master-Slave Determination + Acknowledgment Terminal Capability Set Acknowledgment – Master-Slave Determination + Acknowledgment Open Logical Channel Open Logical Channel (OLC) Acknowledgment with IP Address + Port from Side B RTP Media Stream H.225 Release Complete RAS (DRQ) RAS (DCF) RAS (DRQ) RAS (DCF) GK Establish H.225 Signaling Channel (TCP Connection) Endpoint 1Endpoint 2 Open Logical Channel Open Logical Channel (OLC) Acknowledgment with IP Address + Port from Side A RTP Media Stream RTP Gatekeeper H.323 to H.323 Endpoints

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v RTP H.323 IP Phone A SCCP Cluster A XY WAN (Frame Relay) H.323 to Skinny Client Call Flow Diagram

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v H.323 Client to Skinny Client Call Flow H.323 ClientCisco CallManagerCisco IP Phone H.225 Setup Station Set Lamp (Blink) Station Set Ringer (On) Station Set Lamp (Steady) Station Start Media Transmission Station Set Ringer (Off) Station Off Hook H.245 Master-Slave Determination H.245 Terminal Capabilities Set H.245 Open Logical Channel Station Call Information H.225 Setup Ack H.225 Alerting Station Start Media Reception H.245 Open Logical Channel ACK H.245 Terminal Capabilities Set ACK H.245 Master-Slave Determination ACK H.225 Connect Conversation Station On Hook H.245 Request Channel Close H.245 Request Channel Close ACK Station Stop Media Reception Station Stop Media Transmission H.225 Release Complete Station Set Lamp (Off) ACK = Acknowledgment

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v MGCP Protocol Functionality MGCP is a master-slave protocol, where the gateways are expected to execute commands sent by the call agents. MGCP contains simple endpoints; a simple endpoint executes a small set of simple transactions as instructed by the call agent.

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Endpoint ConfigurationEPCF(CA EP) Create ConnectionCRCX(CA EP) Modify ConnectionMDCX(CA EP) Delete Connection DLCX(CA EP) Notification RequestRQNT(CA EP) Notify NTFY(CA EP) Audit EndpointAUEP(CA EP) Audit ConnectionAUCX(CA EP) Restart In ProgressRSIP(CA EP) MGCP primitives CA = Call Agent EP = Endpoint MGCP Messages

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v MGCP Protocol Functionality Endpoint Identifiers: have two components that are both case insensitive: –Domain name of the gateway that is managing the endpoint –Local name within that gateway AALN/S1/SU0/0 = Slot 1/SubUnit 0/Port 0

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Gateway Cisco CallManager TCP Socket Open Open completes RSIP (Restart) Simple Acknowledgment 200 OK Audit Endpoint (AUEP) Acknowledgment with Endpoint Information Request Notify (RQNT) RQNT R: L/hd (One per endpoint) Simple Acknowledgment 200 OK (One per endpoint) Registration and Endpoint

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v MGCP FXS Call NTFY O: L/hd RQNT R: L/hu,D/[0-9*#] S:dl NTFY O: 4 RQNT R: L/hu, D/[0-9*#] S: NTFY O: 5 CRCX Cisco CallManger VG200 MDCX 200 OK (RTP Port Information)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v SIP Basics SIP originally defined in RFC 2543; reintroduced in RFC 3261 Peer-to-peer protocol where end-devices initiate sessions Defines the signaling mechanism for multimedia conferences SIP uses several existing IETF protocols: –HTTP 1.1 –Session Description Protocol (SDP)media negotiation –Real-Time Transfer Protocol (RTP)media –Domain Name Service (DNS)name resolution –OthersDHCP, MIME, TFTP Text-based ASCII for easy implementation and debugging

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Legacy PBX SIP Proxy, Registrar, and Redirect Servers SIP User Agents (UAs) Application Services LDAP SQLXML SIP RTP SIP CPL 3pcc CAS or PRI SIP Architecture and Agents PSTN SQL = Structured Query Language

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Cisco CallManager SIP Trunk Cisco IOS SIP Gateway Microsoft Messenger Cisco SIP IP Phone Voice mail Apps SCCP Phones SoftPhones Conf XCODE SCCP MGCP CTI SIP

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v SIP Network Cisco SIP Proxy Server 1. SIP IP Phone contacts registrar server to resolve destination SIP address. 2. Cisco SIP proxy server sends INVITE messages to calling and called parties. 3. SIP IP Phones acknowledge the INVITE message and contact each other directly. The IP Phones stream audio through RTP. 1 SIP IP Phone 2 2 RTP 3

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Cisco SIP Proxy Server Installs on Linux- or Solaris-based platforms Functions as a redirect or registrar server Translates E.164 numbers to URL via location server protocols such as Telephone Number Mapping (ENUM) Performs gateway and Domain Name System (DNS) routing

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v ISDN Architecture 64-kbps BISDN 64-kbps Switched and Nonswitched Packet Switching Frame Mode ISDN Switch ISDN Switch CPE Common Channel SIG

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Q or 4 4 or OctetBits Protocol Discriminator (Q.931) Length of CRV Call Reference Value (1 or 2 bytes) Information Element Identifier Length Information Element Identifier Contents of Information Element Next Information Element, and so on CR Flag Message Type 0 0/1 Call reference: establishes a unique value between the user and the network Message type: can be grouped into call establishment, call information phase, call clearing and miscellaneous Information elements: are self-contained entities that further define the message

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Typical Q.931 Messages Calling Party NetworkCalled Party Setup Connection Acknowledgment Setup Acknowledgment Connect Alerting Call Proceeding Connection Acknowledgment Information Call Proceeding Alerting Connect

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Cisco IP Phone Cisco CallManager Cisco IP Phone Conversation Station Set Lamp (Off) Station Off-Hook Station Play Tone (Dial Tone) Station Digit Dialed Station Set Lamp (Steady) Station Stop Tone (Dial Tone) Station Digit Dialed Station Play Tone (Ringback) Station Start Media Transmission Station Start Media Reception Station Play Tone (Off) Station Stop Media Transmission Station Stop Media Reception Station Call Information Station Set Ringer (On) Station Set Lamp (Blink) Station Off-Hook Station Set Ringer (Off) Station Start Media Transmission Station Start Media Reception Station Set Lamp (Steady) Station On-Hook Station Stop Media Transmission Station Stop Media Reception Station Set Lamp (Off) Station On-Hook Station Connectivity and Call Flow

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Skinny Intracluster Calls Registered Cisco CallManager Cisco CallManager A Cisco CallManager B 1000 calls 1001 Cisco CallManager Cluster Skinny RTP Stream

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Registration Process Cisco CallManager YEILD Cisco TFTP DHCP 1. Inline power-capable switch sends FLP 2. Switch provides VLAN information to IP Phone 3. IP Phone sends DHCP request; receives IP information and TFTP server address 4. IP Phone gets configuration from TFTP server 5. IP Phone registers with CCM server

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Device Requirements Active connection maintenance: –RTP streams between devices Disconnect supervision: –End user –Timed –MSF Switchover algorithm: –Graceful –Immediate PSTN Switch Cisco CallManager 1A Cisco CallManager 1B IP PhoneGateway RTP SCCP MGCP

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Cisco CallManager Trace Trace performs three main functions: Configures trace parameters Collects trace parameters Analyzes trace data for troubleshooting problems Major change in trace gathering process between Cisco CallManager 3. x and 4.0(1).

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trace Filter Settings

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Gathering Trace Files

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Viewing XML Trace Files

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Troubleshooting Trace Setting: Cisco CallManager 4.0

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Troubleshooting Trace Setting: Cisco CallManager 4.0 (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Troubleshooting Trace Setting: Cisco CallManager 4.0 (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trace Collection Tool: Cisco CallManager 4.0

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trace Collection Tool: Cisco CallManager 4.0 (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trace Collection Tool: Cisco CallManager v4.0 (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trace Collection Tool: Cisco CallManager 4.0 (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trace Collection Tool: Cisco CallManager 4.0 (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trace Collection Tool: Cisco CallManager 4.0 (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trace Collection Tool: Cisco CallManager v4.0 (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trace Collection Tool: Cisco CallManager 4.0 (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trace Collection Tool: Cisco CallManager 4.0 (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v :05: :20: CCM|StationInit - InboundStim – OffHookMessageID tcpHandle=0x5138d98 15:20: CCM|StationD - stationOutputDisplayText tcpHandle=0x5138d98, Display= :20: CCM|Digit analysis: match(fqcn="", cn="1001", pss="", dd="") 15:20: CCM|Digit analysis: match(fqcn="", cn="1001", pss="", dd="3") 15:20: CCM|Digit analysis: match(fqcn="", cn="1001", pss="", dd="33") 15:20: CCM|Digit analysis: match(fqcn="", cn="1001", pss="", dd="333") 15:20: CCM|Digit analysis: match(fqcn="", cn="1001", pss="", dd="3333") 15:20: CCM|Digit analysis: analysis results Example Trace: H.323 Client to IP Phone

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Example Trace: H.323 Client to IP Phone (Cont.) |CallingPartyNumber=1001 |DialingPattern=3333 |DialingRoutePatternRegularExpression=(3333) |PretransformDigitString=3333 |PretransformPositionalMatchList=3333 |CollectedDigits=3333 |PositionalMatchList= :20: CCM|Locations:Orig=0 BW=-1 Dest=1 BW=64 (-1 implies infinite bw available) 15:20: CCM|StationD – stationOutputCallInfo CallingPartyName=1001, CallingParty=1001, CalledPartyName=, CalledParty=3333, tcpHandle=0x5138d98

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Example Trace: H.323 Client to IP Phone (Cont.) 15:20: CCM|Out Message -- H225SetupMsg -- Protocol= H225Protocol 15:20: CCM|MMan_Id= 1. (iep= 0 dsl= 0 sapi= 0 ces= 0 IpAddr=e24610ac IpPort=47110) 15:20: CCM|StationD - stationOutputCallInfo CallingPartyName=1001, CallingParty=1001, CalledPartyName=, CalledParty=3333, tcpHandle=0x5138d98 15:20: CCM|In Message -- H225AlertMsg -- Protocol= H225Protocol 15:20: CCM|StationD - stationOutputOpenReceiveChannel tcpHandle=0x5138d98 myIP: e74610ac ( ) 15:20: CCM|StationD - ConferenceID: 0 msecPacketSize: 20 compressionType:(4)Media_Payload_G711Ulaw64k 15:20: CCM|H245Interface(3) paths established ip = e74610ac, port = :20: CCM|H245Interface(3) OLC outgoing confirm ip = e24610ac, port = :20: CCM|MediaManager - wait_AuConnectInfo - received response, forwarding

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Example Trace: H.323 Client to IP Phone (Cont.) 15:20: CCM|In Message -- H225ConnectMsg -- Protocol= H225Protocol 15:20: CCM|StationD - stationOutputCallInfo CallingPartyName=1001, CallingParty=1001, CalledPartyName=, CalledParty=3333, tcpHandle=0x5138d98 15:20: CCM|MediaCoordinator - wait_AuConnectInfoInd 15:20: CCM|StationD - stationOutputStartMediaTransmission tcpHandle=0x5138d98 myIP: e74610ac ( ) 15:20: CCM|StationD - RemoteIpAddr: e24610ac ( ) RemoteRtpPortNumber: msecPacketSize: 20 compressionType:(4)Media_Payload_G711Ulaw64k 15:20: CCM|Locations:Orig=0 BW=-1Dest=1 BW=6(-1 implies infinite bw available)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Example Trace: H.323 Client to IP Phone (Cont.) 15:20: CCM|StationInit - InboundStim – OnHookMessageID tcpHandle=0x5138d98 15:20: CCM|ConnectionManager -wait_AuDisconnectRequest ( , ): STOP SESSION 15:20: CCM|MediaManager - wait_AuDisconnectRequest - StopSession sending disconnect to (64,5) and remove connection from list 15:20: CCM| Device SEP003094C26105, UnRegisters with SDL Link to monitor NodeID= 1 15:20: CCM|StationD - stationOutputCloseReceiveChannel tcpHandle=0x5138d98 myIP: e74610ac ( ) 15:20: CCM|StationD - stationOutputStopMediaTransmission tcpHandle=0x5138d98 myIP: e74610ac ( ) 15:20: CCM|In Message -- H225ReleaseCompleteMsg -- Protocol= H225Protocol

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Summary The Cisco CallManager servers in a cluster use SDL links to establish calls between devices registered to different Cisco CallManager servers, while media connections between devices involved in a call are RTP streaming sessions that occur directly between the devices. ITU-T H.323 specifies the protocol architecture for multimedia communications over unreliable networks such as IP. MGCP consists of three main elements: endpoints, commands, and events or signals. SIP is an ASCII-based, application-layer control protocol that VoIP equipment can use to establish, maintain, and terminate calls between two or more clients. Q.931 is the connection control protocol for ISDN connections and is roughly comparable to TCP in the Internet protocol stack. The H.323 recommendation for the stations provides mechanisms for establishing, controlling, and clearing information flows. The three device requirements for supporting call preservation are active connection maintenance, disconnect supervision, and switchboard algorithm. The Cisco CallManager Trace tool performs three main functions: configuring trace parameters, collecting trace parameters, and analyzing trace data for troubleshooting problems.

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Lesson Review 1. Which of these protocols does the CCM NOT use for signaling? 2. Which of these H.323 components does codec use for negotiation? 3. Which of these servers is NOT a valid SIP server? 4. ISDN uses the Q.931 protocol for connection control. Which other protocol uses Q.931 for this same purpose? 5. Which two of these H.323 functions does the CCM handle when connecting a call between two Skinny-based Cisco IP Phones? 6. What type of protocol is MGCP? 7. Which type of call preservation failover method do Cisco IP Phones support?