3Com® VCX V7111 VoIP Gateway User Guide 247CHAPTER 8: T ELEPHONY C APABILITIESWorking with Supplementary ServicesThe V7111 SIP FXS and FXO gateways support the following supplementary services: Call Hold / Retrieve; see Call Hold and Retrieve. Consultation / Alternate; see Consultation / Alternate. Transfer (Refer + Replaces); see Call Transfer. Call Forward (3xx Redirect Responses); see Call Forward. Call Waiting (182 Queued Response); see Call Waiting. Message Waiting Indication (MWI); see Message Waiting Indication.To activate these supplementary services (Hold, Transfer, Forward, Waiting and MWI) on theV7111 gateway, enable each services corresponding parameter either from the WebInterface or using the ini file. Note that all call participants must support the specific usedmethod.When working with application servers (such as BroadSoft’s BroadWorks) in clientserver mode (the application server controls all supplementary services and keypadfeatures by itself), the gateways supplementary services must be disabled.Call Hold and RetrieveInitiating Hold/Retrieve Active calls can be put on-hold by pressing the phone's hook-flash button. The party that initiates the hold is called the holding party; the other party is called theheld party. After a successful Hold, the holding party hears a Dial Tone. Call retrieve can be performed only by the holding party while the call is held and active. The holding party performs the retrieve by pressing the hook-flash. After a successful retrieve, voice is connected again. Hold is performed by sending a REINVITE with the IP address 0.0.0.0 or a=sendonly inthe SDP according to the parameter HoldFormat.
