HT813 on UCM62XX FXO


on UCM62xx unfortunately Zero Config allows you to configure the FXS part of HT-813 but not the FXO part. On the contrary, it is misleading because it sees 2 FXS,
other than that I can not in any way record FXO of HT-813 SU ucm, can someone kindly give me a hand step by step?
(I’ve never seen an FXO before)

I’ve read the manuals but they’re very vague.


Do you have a PSTN - POTS line ?


Of course I do,
I’m just trying to get familiar with the FXO part of the HT-813 and I can’t, it seems strange to me that Zero Config doesn’t allow the configuration of FXO.


It should come up in your FXO lines of the system … try there in the drop down.


in my opinion there is nothing that concerns the FXO part, and for absurdity speaks of 2 FXS when it has only one


What does the trunks area say for your UCM


I don’t see anything in the trunks that could be about adding HT813, exactly what do you mean?


can you add a trunk - does the FXo of the HT813 appear then ?


I don’t think so, but if you know where to look, tell me.




those are the internal FXO of the UCM (I have a UCM6208 and of course I can create 8), those I know perfectly.
I’m talking about adding/recording an external Trunk PSTN (via HT-813) to the UCM.
It should be a simple thing, but apparently it’s not.


that is the area to create analogue fxo trunks, does it appear there as part of the choices or not?


I don’t think so, if you know where you’d rather tell me or give me a screen, thank you.


My guess is that GS is using a common GUI for the likes of the HT813, HT502, and others of similar ilk and it shows the two FXS ports rather than 1 FXS and 1 FXO. The UCM does not have templates for any of the FXO devices such as the GXW410X devices.

ZC is apparently only set to deal with user endpoints rather than trunk type devices as there is no template for their PRI devices as well (but these are rather new).

I take it to be an error on their part and the FXO side has to be manually set as a SIP trunk in the UCM, where a peer trunk would be the easier implementation.


yes in fact @lpneblett
Can you kindly tell me the various steps? I guess I have to configure FXO of HT813 towards a Trnk Peer of Ucm.


Sure, but it will be a bit before I get into the office today.


quiet, when you can, we would miss :slight_smile:


I managed to get the HT-813 to work, but I do detect two anomalies:

1 - I have some echo effect on HT-813 (on the original PSTN there is no echo), I tried to modify both “Disable Line Echo Canceller (LEC)” and “Disable Network Echo Suppressor” but the echo persists, advice?
2 - when receiving on UCM the call starts ringing after 3-4 rings, I can not find how to decrease these rings (the PSTN connected to an analog phone rings immediately).

Does anyone know the solution?


  1. In the FXO settings (as well as the FXS) there are settings to adjust the TX and RX gain. Adjust these.


1 - test, thanks -> (should the gain only serve to increase / decrease the sound?)
2 - unfortunately the “Number of Rings” parameter does not work, any parameter you set rings after 4 rings, I just reported it in a Helpdesk