analog phone, loop start, voice gateway ground start

[sarahr202]

Hi every body.

analogphone1--------fx0-Voice-gateway

Our analogphone1 is a typical phone which uses loop start signaling while our voice gateway uses ground start signaling on its fxo connected to analogphone1. The question is what will happen if if we pick up the handset of anlogphone1? will voice gateway still detect that handset is off hook?

thanks and have a great weekend.

[Jeff Van Houten · Accepted solution]

Fxo ports should point back to the CO. Fxs ports should be connected to end devices like a an analog phone.
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[Harmit Singh · Accepted solution]

Hi Sarah,

Like Jeff righfully pointed out, your analog phone should be connected to an FXS port and not FXO. Secondly, FXO ports on voice gateways can be configured for loopstart (default) or groundstart. Here is a nice doc on CSC which talks about this:

https://supportforums.cisco.com/docs/DOC-2906

HTH.

Regards,

Harmit.

[sarahr202]

Thanks Harmit.

Sorry about the typo. Please concider the port connected to analgphone as fxs .

Now let revisit the same scenario:

analogphone1-------fxs-Voice gateway

analogphone( loop start)

FXS  ( ground start)

what will happen if we pick up the handset of analogphone?

Thanks and have a great day.

[Harmit Singh · Accepted solution]

Hi Sarah,

Good day! So what you're saying is:

Analog Phone (LS) --- FXS port (GS) --- GW

You cant configure the analog phone to do LS or GS. It is a dumb device. The voice-port can be configured for either of the two. However, I dont see any reason why you would want to configure the FXS port to be GS when connecting an analog phone to it.

HTH.

Regards,

Harmit.

[sarahr202]

Thanks Harmit.

I was just curious other than that no particular reason for configuring fx to be GS.

You are saying analogphone is dumd device( not dumber than me :-  ,see  i can not  even spell dumb correctly)

So when pick up the hand set, it just completes the circuit, allowing dc current to flow.  Fx port if configured for LS, senses the current flow , If FX is configured for GS, it measures the potential difference.  The point I am trying to make regardless what you have configured at FX site, the only thing analogphone does is to complete the circuit when we pick up the handset.It is upto FX how to interpret this  which off course depends upon if fx port is configured for LS or GS.

Is my understanding correct ?

[Harmit Singh · Accepted solution]

Hi Sarah,

Bingo! that is correct! :-)

Regards,

Harmit.

[sarahr202]

thanks Harmit