Basics: 1861; FXS; FXO, IP Fone and Analog fones

Answered Question
May 18th, 2008
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HI; iam bit new to IP telephony; say i have 1861 router with 4 FXS,4 FXO &8 port PoE sw, i understand that 8 IP fones will be connected to 8 port questions:

1- Can i plug normal analog fones to FXS (i believe i can) ; if yes than traffic will go to WAN or PSTN

2-FXO will use for what??? Are they serve

for same purpose as PRI's serve but giv

single call facility over WAN/ FXO port

If any body can elaborate when traffic go to WAN and when PSTN??? it really confuses me.

Correct Answer by Kenneth Mohammed about 9 years 1 month ago

You are correct!

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Overall Rating: 4.8 (3 ratings)
Kenneth Mohammed Sun, 05/18/2008 - 08:08
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Hello Omair,

To answer your questions:

1. Yes, you can plug normal analog phones to the FXS ports on the router. The traffic will go wherever you want it to go, based on the number dialed (dial-peer configuration)

2. FXO is used for the line coming in from your telco. These are standard analog POTS lines. If you have a PRI, then you will have to get a VWIC-1MFT-T1/E1 or VWIC-2MFT-T1/E1 card to support the PRI or PRI's.

3. The phone traffic will traverse the WAN if you have implemented site to site dialing or toll bypass, and you have dial-peers configured, which basically tell the router, when number xxxx is dialed, send this call across the WAN, while you may have another dial peer that states when number xxx-xxx-xxxx is dialed, to send this call out to the PSTN.

Hope that made sense.

omair.siddiqui Tue, 05/20/2008 - 05:39
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thanks kenneth

That helps a lot ..u really made it simpler for me... just need per my understanding

4 FXS: is for 4 analog fones (or other devices)

8 Port Switch: is for connecting 8 IP fones

4 FXO: is for atmost 4 connecion to PSTN

Serial/WAN card: will be used as gateway to route calls over WAN

Plz let me know i am wrong somewhere


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