Nortel Networks NN10029-111 manual Network/Address Hiding service

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Nortel Networks Confidential	Overview 19

The Converged service adds the following capabilities to the end user's telephony service:

•the ability to manually redirect incoming calls to another party from the PC

•the ability to set up automated enhanced routing and screening of incoming calls based on time of day or based on the calling party's identity

•a call log of all incoming calls

•the ability to send instant messages to the party on the other end of a call

•the ability to start collaborative applications such as shared whiteboard, file transfer, and clipboard transfer with the party on the other end of the call

•the ability to receive a picture ID of the party on the other end of the call

Network/Address Hiding service

The SIP Application Module uses SIP and the Session Description Protocol (SDP) to coordinate the establishment of multimedia sessions for signaling and media, respectively. These protocols embed IP information in their messaging. While Network Address Translation (NAT) devices change port and address information in the IP packet header, most are not currently SIP or SDP aware. IP addresses in these messages are therefore sent out unchanged through the NAT. If the SIP Application Module were to forward these messages on unchanged, sensitive IP information would be given to untrusted clients. In order to remedy this, the SIP Application Module sanitizes the messages before forwarding them.

For IP information in the SIP headers, the SIP Application Module either removes the header (for example, Via headers) or replaces the IP address with the address of the SIP Application Server (for example, Contact header). A media portal is necessary in order to replace the IP information in the SDP headers. The SIP Application Module queries the Media Portal (using MGCP+) for a new IP and port combination to replace the IP and port put there by the client. This effectively anchors the media stream at the Media Portal.

Clients therefore see the SIP Application Module as their signaling endpoint and the Media Portal as their RTP media endpoint. They have no knowledge, and therefore no IP information, about the other client they are in a session with.

Copyright © 2003, Nortel Networks

MCP SIP Application Module Basics

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Contents MCP SIP Application Module Page How this chapter is organized OverviewFunctional description OverviewAgent Client Internal Protocol Back-to-Back User Agent service UserANetwork configuration BiggerMart.com BigMart.comPublic network InterfacesProtocols PCPSQL Hardware Services and featuresRouting and Translation services Foreign termination Local termination Call Transfer serviceTelephony routing Relationship between Telephony routing stages SIP Aliases Multiple Route Termination Call Processing Language Interworking services Discriminator serviceBearer Path Control Privacy Control serviceService package enforcement Authentication servicesConverged PC service Network/Address Hiding service Enterprise Clients Notification support Presence Instant MessagingVoicemail server interoperability and MWI Nortel Networks Confidential Overview Registration-static and dynamic Overload control Network address bookReliability and fault tolerance Manual failover OAM&P strategy Updating the SIP Application Module software UpgradesUpdating the Application Module from the menu tree Updating the SIP Application Module from the pull-down menu Load list for updating Progress of update Page Procedure 1 Clearing the SLE701 Slee Health Monitor alarm Alarm clearing proceduresProcedure 2 Clearing the SMDI101 alarm Configuration Configuration Nortel Networks Confidential Displaying help text Adding a component Procedure 1 Adding a componentAdding a component Configuration window top half Adding Services Progress dialog box Configuring the SIP Application Module tabs Field Value Description Application Server tab field descriptions Sheet 2Configuration Nortel Networks Confidential Nortel Networks Confidential Configuration Configuration Nortel Networks Confidential URL Configuration Nortel Networks Confidential Nortel Networks Confidential Configuration Configuration Nortel Networks Confidential Completing the Database Base tab fields DNS SRV Completing the Data Synchronization tab fields Locate User Svc tab field descriptions Sheet 2Configuration Nortel Networks Confidential Nortel Networks Confidential Configuration Configuration Nortel Networks Confidential Nortel Networks Confidential Configuration Completing the Local Accounting Manager tab fields Completing the In Memory Database tab fields Configuration Nortel Networks Confidential Memory Database tab field descriptions Sheet 2 Completing the Location Service tab fields Location Service tab field descriptions Sheet 2 Configuration Nortel Networks Confidential Nortel Networks Confidential Configuration Configuration Nortel Networks Confidential Nortel Networks Confidential Configuration Privatestaticaddress whose value Server.blade.host.label forCompleting the Server Subscription tab fields Addrsip Porthttp Portprotocol Nortel Networks Confidential Configuration Configuration Nortel Networks Confidential Nortel Networks Confidential Configuration Configuration Nortel Networks Confidential SipFwdAdapter tab field descriptions Sheet 2 Completing the Transport Management tab fields Nortel Networks Confidential Configuration Configuration Nortel Networks Confidential Nortel Networks Confidential Configuration Configuration Nortel Networks Confidential Nortel Networks Confidential Configuration Figure above Nortel Networks Confidential Configuration Transport Management tab subfields, cont’d Transport Management tab subfield descriptions Active-standby server group configuration Nortel Networks Confidential Configuration Example Additional SIP TCF Base tab configuration informationTCF Config details UDP/TCP/SSL Config values Parameter Value DescriptionRetransmission Off parameter Invite Timer parameterTime Transaction parameter Add Defaults parameterCheck Mandatory Headers parameter Accounting management Page Performance management Page Security Security and AdministrationPage Voice plus video Appendix a Basic call flowsClient-to-client voice plus video diagram Application Client a Module Client B Client-to-client voice plus video call flowCall transfer Call transfer to client diagram Client a Client C Client BApplication Client a Module Client B Client C Call transfer blind to client call flowAppendix a Basic call flows Nortel Networks Confidential Failed call transfer call flow Appendix a Basic call flows Nortel Networks Confidential Authentication diagram AuthenticationApplication Client a Module Database Authentication call flowNortel Networks Confidential Appendix a Basic call flows Page Page Page Page MCP SIP Application Module