TTML links work like a charm when alls fine.
However to get them working is a pain.
Let me illustrate this with an example.
We use simple cisco routers at both the ends & TTML provides their LOOP modems & other Leased Line Infrastrcutre (i.e the 4 wire and TTML Mux).
But as Murphy's LAW suggests, If things can go wrong, they certainly will.
Same was the case with us for several TTML links wherein we spent tremendous man days in getting the link up and working.
We use E1 controllers at central site & V.35 Smart Serial Interface at the spoke.
This caused the TTML link to show up tremendous errors on the link, despite the fact that the end to end physical 4 wire loop for over 48hrs resulted in no errors.
So as usual, the modems, the pair were replaced. However no luck!
Eventually the winning combination for TTML links with E1 controllers is
Set modems to Framed 1984Kbps & there is a proprietary feature in LOOP modems, called TTM. Once this is set, you are good to go.
Hope some TTML guys read this and make this a standard practise in their installations whenever an E1 controller card is involved
