Troubleshooting Network Infrastructure © 2004 Cisco Systems, Inc. All rights reserved. Troubleshooting Gatekeepers and SIP Trunks IPTT v4.04-1

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Troubleshooting Gatekeeper: Objectives Upon completing this lesson, you will be able to: Describe the role of a Gatekeeper in an AVVID network Identify common voice issues related to Gatekeeper configurations Discuss the signaling between CCM and a Gatekeeper and identify common issues and troubleshooting tools Describe Cisco SIP Trunk Operation with CCM

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Outline Overview Gatekeeper Overview Troubleshooting Gatekeepers with Gateways and Cisco CallManager Gatekeeper and Cisco CallManager Call Processing Troubleshooting Cisco SIP Trunks Summary Quiz

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Gatekeeper Overview

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Gatekeeper Messages

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v RAS Signaling Directed Endpoint Signaling The RAS channel is opened before any other channel and is independent of the call setup and media transport channels.

© 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 (H245 address) Terminal Capability Set + Ack Master/Slave Determination Terminal Capability Set – Master/Slave Determination + Ack Terminal Capability Set Ack – Master/Slave Determination + Ack Open Logical Channel (OLC) Open Logical Channel (OLC) Ack 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) A B Open Logical Channel (OLC) Open Logical Channel (OLC) Ack with IP address + Port from side A RTP media stream RTP Gatekeeper H.323 Call Flow

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Call Flow with Gatekeeper: Intrazone Single Zone Gatekeeper

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Call Flow with Multiple Gatekeepers: Interzone Multizone Gatekeeper

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Troubleshooting Gatekeepers with Gateways and Cisco CallManager Check List 1. Verify GK configuration Does the gateway/Cisco CallManager belong to one zone? Verify that the dial plan is correct. Verify that the technology prefix is correct. Is bandwidth configured between zones? 2. Verify GK on gateway/Cisco CallManager Check device pool (codec usage) Verify check. 3. Verify gateway/Cisco CallManager registration with GK show gatekeeper endpoints debug ras debug h225 asn1 4. Verify call setup with GK debug ras show gatekeeper calls show gatekeeper zone status debug h225 asn1

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Common Gatekeeper Issues Use: debug h225 asn1 Four of the most common issues between gateways and gatekeepers: –RRJ: rejectReason duplicateAlias –RRJ: rejectReason terminalExcluded –RRJ: rejectReason securtyDenial –RRJ: rejectReason invalidAlias

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Call Setup E.164 Lookup 2 4 Call Setup 4 8 Ring 8 5 E.164 Lookup 5 7 Call Setup 7 Alerting 9 9 GK Connect RTP Stream 13 Call Admission Connect Off-Hook 11 Ringback 10 Gatekeeper and Cisco CallManager Call Processing IP WAN

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Troubleshooting SIP Trunks SKINNY Client SIP Client

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Basic Outgoing Call: IP Phone to SIP Gateway plays ringback CCM establishes Media ACK RTP Stream 1 BYE CCM releases Media resource hangs up RTP Stream OK 100 Trying 180 Ring 200 OK with SDP INVITE with SDP OpenReceiveChannelAck(rtpAddress) SIP GW MTP OpenReceiveChannelAck(prerredCodec telephone-event)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Basic Incoming Call: SIP Gateway to IP Phone CCM establishes Media RTP Stream 1 BYE CCM releases Media resource hangs up RTP Stream OK 100 Trying 180 Ring 200 OK with SDP INVITE with SDP SIP GW MTP ACK Answer Ringing

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Performance Monitor SIP Counters

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Performance Monitor MTP Counters

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v SIP Settings CCM SIP Traces

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Destination Port 5060Incoming Port 5060 Destination Port 5061Incoming Port 5061 Outgoing Transport Type: Cisco CallManager to Cisco CallManager = TCP Cisco CallManager to CSPS = UDP unless Record Route option is configured Correct Destination Port 5060 Incoming Port 5060 Destination Port 5060 Incoming Port 5060 Cisco CallManager or CSPS Cisco CallManager Incorrect Troubleshooting SIP Trunk Cisco CallManager Cisco CallManager or CSPS CSPS = Cisco SIP Proxy Server

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v SIP Trunk Started

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v IP Port 5060, 5061 and 5062 Listening Cisco CallManager Listens for SIP Trunk Ports

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Invite Message Incoming Port 5060 Protocol Analyzer

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Invite retries from 500 ms, 1 s, 2 s, 4 s, 8 s, 16s Prack retries from 500 ms, 1 s, 2 s, 4 s, 4 s, 4 s, 4 s, 4s Stay with defaults! SIP Service Parameters

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v SIP Prack timer SIP PayLoadType for DTMF Enable Prack for Reliable 1xx transmission SIP Service Parameters (Cont.)

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Summary Gatekeepers provide CAC and bandwidth control. RAS signaling is done using the Directed Route Signaling. RAS signaling for gateways and Cisco CallManager servers are the same. RAS messages are sent using H.225 messages over UDP. End devices establish call setup, not the gatekeeper. Cisco CallManager uses port 1720 to listen to H.323 devices. After Open Logical Channel and OLC ACK, the IP address and port number are sent from the other side, then the audio stream is established. To troubleshoot gatekeepers, gateways and Cisco CallManager, check the zones and technology prefix matches on the gatekeeper. Two types of Cisco CallManager gatekeeper-controlled trunks are ICT and H.225.

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Summary (Cont.) Active capabilities and waiting for the other site to initiate the capabilities check box is new in Cisco CallManager 4.0(1). Gateway and Cisco CallManager call rejection issues can be seen using various show and debug commands. An MTP device is used to allow a Cisco CallManager SCCP device to talk with SIP Phones. The MTP check box is on by default and cannot be unchecked. SIP Phones send DTMF payload in-band; IP Phones send tone out-of-band; MTP converts payload so Cisco CallManager can understand the tones. Use Performance Monitor as a troubleshooting tool for all Cisco CallManager issues, including MTP and SIP devices. Use Cisco CallManager traces when troubleshooting Cisco CallManager-to-SIP call setup. Use the netstat -a command to see if Cisco CallManager is listening to incoming SIP trunk ports.

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Lesson Review 1. Is the exchange of terminal capabilities, a function of gatekeeper? 2. What RAS message is used by one gatekeeper to another when trying to find a destination endpoint? 3. A gateways registration to a gatekeeper was rejected, which RAS message is sent by the gatekeeper? 4. After a gateway sent a RRQ to the gatekeeper and received a RCF, what is the next expected RAS message sent by the gateway? 5.H.225 Call-Setup uses what protocol for transport? 6.H.245 Call Control uses what protocol for transport? 7. RAS H.225 uses what protocol for transport? 8. After Open Logical Channel Ack is sent from the far end, what additional information is sent? 9. A gatekeeper is required in a VoIP network? 10. You are having calls rejected by the CCMs registered gatekeeper, what command would you used to show registration, admission and status, messages real-time?

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Lesson Review (Cont.) 11. What is the easiest way to get CCM to register with its registered gatekeeper? 12. What how does a CCM register with its gatekeeper (hint: Gatekeeper Configuration page)? 13. What two types of trunks are used for gatekeeper control? 14.(True or False) With Gatekeeper-Controlled ICT, active caps are off by default? 15. What CCM device allows for SCCP to SIP communication? 16. What monitoring tools can be used to view INVITE packets on the wire?