[Asterisk-Users] Intel 536ep as a FXO?

[Steve Underwood]

Andrew Kohlsmith wrote:

> [...]
>
>Not at all.  Any of the channel banks I've tested have better echo and audio 
>quality than the X100P.  I believe it comes down to the Part68 interface 
>being better able to accomodate different lines but YMMV.  I have never had 
>decent results with an X100P.  All of the tricks and hacks you see on the 
>wiki with it are proof that it's a substandard card, IMO.
>  
>
If you are trying to do cellular, satellite, VoIP  or any telephony with 
high latency and do not use echo cancellation you are on to a looser. 
Sure, the problem is worse with some interfaces in combination with 
certain lines (you can't separate the two), but echo performance will 
always be lousy without proper echo cancellation. With echo cancellation 
almost any FXO interface should work well. Every cell phone call to the 
PSTN is echo cancelled. Every cheapo or expensive VoIP interface box 
echo cancels. Hybrids of any design are really lousy, and do little more 
than stop howling. You can hand tweak some of them connected to a 
particular line and get great performance. However, they always drift, 
the lines get altered, or in some other way they get screwed up again. 
Echo cancellation is a requirement, not an option.

If the X100P's interface matches a line well it will work well. If it 
matches it badly it will work badly. Same with the channel banks, or any 
other analogue line interface. Almost all use a compromise line match. 
Adaptive line matching is rare. The echo you get is the luck of the 
draw, regardless of what FXO hardware you are using.

Regards,
Steve