Nortel CS 1000 User Manual

Also see for CS 1000 Series: Fundamentals Manual Installation and commissioning User guide

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Nortel CS 1000 User Manual Manual pdf 17 page image

Overview of SIP DECT 17Primary DN. The additional DN configured in CallPilot is the external DN ofDECT handset, that is, the Target DN on the UEXT corresponding to theDECT handset.Communication Server 1000 only supports the so-called Unsolicited MWINOTIFY modelAn external SIP UA cannot SUBSCRIBE to MWI NOTIFY messages andcannot request the current status of MWI for the DN from the system(by sending SUBSCRIBE messages). Instead of that a SIP UA hasto be ready to get MWI NOTIFY messages from system even if it didnot SUBSCRIBE to those and it has to update MWI according to thosemessages only.Due to the Unsolicited MWI NOTIFY model in Release 5.5, the DECThandset can only rely on the MWI notifications sent by CommunicationServer 1000. Therefore, the MWI indication based on that existingmechanism may not be in the correct state on the DECT handset if thehandset was turned off and then turned on. Also, the MWI indicationmay not be in the correct state if the user of the handset goes out of thecoverage area of the SIP DECT system and then enters the coverage areaagain. In such a situation, the MWI indication on the DECT handset isguaranteed to be in the correct state only after the next MWI state changehappens in the CallPilot system.If a twinned configuration is used for a DECT handset, the correspondingIP or TDM phone always correctly reflects the current state of MWI,assuming that it receives MWI notifications for its Primary DN fromCallPilot.SIP DECT capacity limitationsThe following capacity limitations apply to SIP DECT.• a maximum of 12 simultaneous calls for each DAP• a maximum of 256 DAPs on each network (where hand over andsynchronization between DAPs is possible)• a maximum of 6000 DECT handsets on each SIP DECT system (therecan potentially be several isolated SIP DECT systems connected toCommunication Server 1000)• a maximum of 1000 simultaneous calls on each network• a maximum of 25 subscription records for each DAPIf the planned number of DECT handsets in a SIP DECT system isequal to M, and the number of DAPs in that system is equal to N, Mmust be less than or equal to N*25.Consider the following additional capacity limitations based on theCommunication Server 1000 configuration characteristics.Nortel Communication Server 1000SIP DECT FundamentalsNN43120-123 01.076 January 2009Copyright © 2008-2009 Nortel Networks.