Telkom ISDN Network Terminator Question

AlphA · Post by **AlphA** » 12 Apr 2005, 11:06

Hi guys,

Just a quick question regarding the Telkom ISDN Network Terminator. I have a UPS keeping my P4 and Celeron D alive in the event of a power failure. This morning, I wanted to disconnect from the internet before I left for work, so I thought I'd try a little test. I turned off the wall power switch, thinking it will stop power to the Network Terminator. It obviously did lose power (as its not getting power from my UPS), but the machines kept going. After about 2 mins (I could'nt stand the sound of the UPS beeping constantly!), I turned the power back on, but my ISDN connection was STILL going! Even without power going to the Network Terminator.

Does anybody know why this happened? Would it have dropped the connection after a few more minutes? If not, then why does a Telkom ISDN Network Terminator have a power plug if it can still operate without it?

The reason I'm asking these questions is cos I was thinking of making a cable to connect my Network Terminator to my UPS, so that my internet connection wont die in the event of a power failure...

Any input would be appreciated....

AlpHA

AlphA · Post by **AlphA** » 12 Apr 2005, 18:27

Anybody?? *echo*

Abatis · Post by **Abatis** » 12 Apr 2005, 18:42

i think when it loses power it goes to a sort of emergency mode with just one channel working

meaning it should work fine but all the other channels would not function at all

could you verify this by checking if you can place a call ?or if you are running 128 isdn check if the speed dropped to 64

Jasonhk · Post by **Jasonhk** » 12 Apr 2005, 20:42

Jess that is strange so the TA lost power but the PC was still on through the ups...Windows just proably though it was still connected..

What you can do a very easy solotuion, take the plug from the ups but it and attatch a 3 x Plug adapter onto it then you can use normal plugs.

AlphA · Post by **AlphA** » 13 Apr 2005, 08:48

Thanks for the responses guys...

Abatris --> You could be correct. I was connected to the net at 64Kps...so your response could possibly be correct. When I get home from work, I will test what you say....will try to make a call while dropping the power supply. If this 'emergancy mode' thing holds true, then its cool....I would'nt have to hook up the Terminator to my UPS...

Jasonhk --> My TA is not connected to my UPS at all...I was planning on making a 3 pin plug and hook that to the UPS to power the TA, but like I said, it this 'emergancy mode' holds true....there may not be a need for that.

I will test it by trying to dial up to work, (or make a call) with the 2nd line on the TA, while the power is dropped. Will let you guys know the response..

Thanks again for the responses..

Sojourn · Post by **Sojourn** » 13 Apr 2005, 17:03

Even if the ISDN modem have a power redundancy, or emergency mode, its still a good idea to let it run through the UPS, if the UPS cater for an ISDN connection type. This way spikes, surges and lightning get absorbed by the UPS and "should not" reach your modem. (Thats for the actual telkom voice/data line.) If you can also hook the power to the ISDN modem up to the UPS, even better.

S

Abatis · Post by **Abatis** » 13 Apr 2005, 17:09

the isdn ta has it's own surge protector for power and the line

Abatis · Post by **Abatis** » 13 Apr 2005, 17:31

i just dug up my old ta manual :
it says that when ac power is not available it draws power from the isdn exchange through the local loop (whatever that means) to provide a restricted power mode and goes to say almost exactly what i said in my first post

AlphA · Post by **AlphA** » 14 Apr 2005, 07:50

Thanks Abatis... Its interesting that it still gets power from the exchange.

There are two lights on the TA....a red and a green light. The green light goes out when you disonnect the AC power, but the red light still burns.

Wonder how long it will receive power from the exchange? Need to test this.

Thanks for all the posts guys....

aXe · Post by **aXe** » 16 Apr 2005, 19:21

Keep us informed on this it is rather interesting, but ADSL is still the route..... are you using InfiniCall?

AlphA · Post by **AlphA** » 17 Apr 2005, 06:58

aXe --> Will post a response on this tomorrow morning., when I intend to diconnect. Dont want to risk losing my connection now as I'm still downloading. And to answer your question, yes I am uing Infiiticall.

Hill · Post by **Hill** » 17 Apr 2005, 07:51

AlphA wrote:Thanks Abatis... Its interesting that it still gets power from the exchange.

There are two lights on the TA....a red and a green light. The green light goes out when you disonnect the AC power, but the red light still burns.

Wonder how long it will receive power from the exchange? Need to test this.

Thanks for all the posts guys....

The exchange should be able to supply power to all its circuit/lines as long as it is powered itself. Be it from its own ac source or from it's back up batteries/generator. (Depends on what Telkom uses)

AlphA · Post by **AlphA** » 18 Apr 2005, 09:04

Well, I tested it this morning....I cut off power and after 5 mins I could'nt tolerate the beeping of the UPS! But, the TA still maintained power from the exchange. I tried to call out, but could'nt.. Seems like Abatis's explanation was correct!

Thanks guys...