Usage Manual: SIP Residential Gateway

IMPORTANT:
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Please do the configuration of the RG as per the CONFIGURATION_MANUAL before
proceeding with using RG.

Before using RG make sure that you can make SIP based voice calls between two
UAs through VOCAL. Refer VOCAL documentation on UA for doing this.


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Using the Residential Gateway
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[1] Load the Quicknet drivers for Linejack into the kernel on the RG machine.
For this do the following:
	/sbin/modprobe ixj

The Linejack will make a clicking sound as the drivers are loaded into the
kernel. Also the LEDs on the back panel of Linejack will glow GREEN if
everything is proper. 

If there are some problems with loading the driver the LEDs will be RED.
Sometimes the driver gets loaded into the kernel but the LEDs remain RED. In
such cases unload the drivers & reload them using the following commands:
	/sbin/rmmod -r ixj
	/sbin/modprobe ixj

Repeat this steps till the LEDs glow GREEN.
NOTE: The above steps have to be carried as user root.


[2] Run RG by typing: 
	rg -q -f rg.cfg


[3] You can make two types of calls through RG -
-- IP-PSTN call
-- PSTN-IP call


IP-PSTN call => Call initiated from UA destined for PSTN
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From UA (say 1001) dial a telephone number preceeded with '9' (for e.g.
95721383). Refer to the README of UA on how to make call using UA.  The RG will
make a call to 5721383 (stripping off '9').  Wait till RG sends ringback. After
a couple of ringbacks the RG establishes RTP path and you shall hear the PSTN
ringback (***). Once the call is answered you can have conversation. Either
party can disconnect the call.

(***) 
LineJack cannot detect that the PSTN user has answered the call. Hence we do
the following workaround. We start a timer of 5 seconds after detection of each
Ringback cadence and stop the timer started by the previous ringback cadence
detection. If the next cadence does not happen before the timeout we conclude
that the PSTN user has answered the call. This technique works b'cos the
Ringback cadences from PSTN are of fixed duration & we can assume that if the
cadence does not occur within that time span the Ringback has stopped and the
call is answered. This technique can fail if the call is not answered at all.
Hence we protect it by providing a ringback cadence detection count. If this
count exceeds 8 we conclude that the call is not answered & RG disconnects on
the PSTN side. As a side effect we donot allow the RG to be hogged for long
durations during call setup.  


PSTN-IP call => Call initiated from PSTN destined for UA
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Call from a PSTN telephone to RG (RG on 5725018). On hearing IP dialtone, in
tone mode dial 1001 for making call to UA 1001. Once the call is answered you
can have conversation. Either party can disconnect the call.

NOTE: RG works in tone mode only.


IMPORTANT 
*********
The above instructions show briefly the basics of how to make IP-PSTN or
PSTN-IP call. For a better understanding of the different scenarios handeled by
RG within IP-PSTN and PSTN-IP calls, it is recommended to go through the
TEST_CASES and the LIMITATIONS_WORKAROUNDS documents.

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Refer to TEST_CASES for testing different call scenarios with RG.

Refer to LIMITATIONS_WORKAROUNDS for the limitations and workarounds.