Asterisk Grandstream Paging

(Revised for GXP-21xx Series Phones) 10-22-2010

Here is an example of two paging methods that can be used from the Grandsteam GXP-20XX and GXP-21XX series.

These methods can be extended to do many paging tasks. Our favorite is using the GXP-XXXX intercom button to trigger a meetme session with all the extensions in an office.

The first method uses the Paging function in the phone.
This is the most natural and allows you to use the phones built-in feature.
You select your line and hit the OK (GXP-2000) button or the MENU (GXP-20XX,GXP-21XX) button
This puts the phone into paging mode then you dial the extension.

The second method is to prefix the extension with an * character.
This is was the traditional method offered by Grandstream on their site, I have provided them with the first method and they are working on a white paper using the first method.

This example was written to run on Asterisk 1.4.x
(We have run modified version with 1.6.x and 1.8.x as well, on 1.8 you must modify the ChanIsAvail it appears that jumping has been dropped.)
Will post a more up to date 1.8.x version when we get ready to go production. - BEZ (zktech)

[Ext-IN]
exten => _2XXX,n,Set(l_Exten=${EXTEN})
exten => _2XXX,n,Set(l_IsPaging=${SIP_HEADER(Call-Info)})
exten => _2XXX,n,GotoIf($["${l_IsPaging}"="answer-after=0"]?callInterCom|1)
exten => _2XXX,n,Goto(Internal,${EXTEN},1)

exten => _*2XXX,1,Set(l_Exten=${EXTEN})
exten => _*2XXX,n,Goto(callInterCom,1)

exten => callInterCom,1,Macro(CoreExtPage,SIP/${l_Exten})

Please note: The s2 line has been modifed for full RFC compliance: This is requried for GXP-21XX series phones. It is backwards compatiable to the GXP-20XX series phones.

[macro-CoreExtPage]
exten => s,1,ChanIsAvail(${ARG1}|js) ; j is for dump and s is for ANY call
exten => s,2,SIPAddHeader(Call-Info: \;answer-after=0)
exten => s,3,NoOp() ; Add others here
exten => s,4,Dial(${ARG1}|j)
exten => s,5, Hangup
exten => s,105,Hangup

- BEZ (zktech) http://www.zktech.com

Please note this Grandstream link is based on the old version of our examples but may be of some help.
Grandstream Paging PDF