SPA232D with Cordless Analogue Phone

[Dmitry Golovenkin]

Hello,

I have a Cisco SPA232d (updates to latest f/w), which is connected to a SIP provider. I am want to connect a standard DECT phone to the FXS port on the SPA232d and make/receive calls. I've managed to get the SIP part working and that's all registered but  I cannot make calls using the phone plugged into the FXS port. If I plug a basic corded phone into the FXS port, then that works fine... what can be the problem?]

Cheers,

Dmitry

[Dan Lukes]

Lets allow me to rephrase your description to verify I got it.

SPA232D configuration is still the same. You have two analog phones - the one is DECT phone, the second one is classic phone. The classic phone is working, while DECT phone doesn't work.

Right ?

Can you be more specific claiming "cannot make calls" ?

[Dmitry Golovenkin]

It looks like the DECT phone (BT Xenon and also tried BT Graphite) do not work with the gateway but a standard analogue phone works. Reading more online, it points to an off-hook issue as the gateway cannot detect if the phone if off hook.

If I plug the DECT phone in and try to call it from outside, the phone displays a call coming in and if I try and answer it, nothing happens. Then the standard phone works fine.

[Dan Lukes]

Well, DECT is not the matter here.

It's just old gold analog POTS kind of line connected to FXS port in all cases you mentioned (either classic or DECT phone). 

Unfortunately, there's nothing like universal world POTS standard. POTS line parameters vary - nominal voltage, characteristic impedance, ground versus loop start signalling, frequency, wave shape and voltage of ring signal, off hook threshold ...

See SLIC specification of SPA112 FXS port.

Reading more online, it points to an off-hook issue as the gateway cannot detect if the phone if off hook. If I plug the DECT phone in and try to call it from outside, the phone displays a call coming in and if I try and answer it, nothing happens.

Incoming call is displayed. Can you pick up it ?

Yes, it look like off-hook detection issue. It's matter of phone's impedance. SPA112 consider line off hook if loop impedance fall bellow 1kΩ. May be your phone impedance is so high, although it's suspicious - most typical closed loop phone impedance is about 300-400Ω

Check DECT phone SLIC specification.