[Asterisk-biz] PRI Hardware Echo Canceller

[Kris Boutilier]

> -----Original Message-----
> From: asterisk-biz-bounces at lists.digium.com
> [mailto:asterisk-biz-bounces at lists.digium.com]On Behalf Of 
> ewr at erols.com
> Sent: Thursday, June 30, 2005 2:43 PM
> To: Commercial and Business-Oriented Asterisk Discussion
> Subject: Re: [Asterisk-biz] PRI Hardware Echo Canceller
> 

> >> Unfortunately, soldering a power supply and cat 5 on to a 20 year old
> >> card from ebay and then putting it all in a shoe box, or trying to track
> >> down (as the wiki calls them) "the highly desireable 2 slot 253C"
> >> shelves, are not really the greatest options for a corporate
> >> environment.
> > ebay usually has those shelves, not the 2-slot ones, but 
{clip}

Myself, I took an 8 slot wire-wrap shelf to a local welding shop and, voila!, 4x 2-slot tig welded shelves.

> Either way, it doesn't solve my problem.  If I am installing asterisk in a 
> small to medium sized office, I would like to find a product that is easy to 
> purchase and easy to connect.  I don't want to rely on something that I 
> *might* be able to get if I watch ebay close enough, never knowing just how 
> much space it needs, how much I will have to pay for it, or 
> if it will  actually work when it arrives.

Tellabs direct customers to either Walker & Associates (800-472-1746) or Greybar (800-825-5517) for all of these units now as they've discontinued development. Most of the 257x cards on the market are generally 1998 or newer. Walker also has shelves, endpath modules and ACE modules in stock. If you're doing a US gov't installation they will also recertify the equipment.

> I didn't really mean to be short in the last email, but it 
> seems (IMHO) that there is a huge need for a current product like this.  
> Evidently they *do* exist, at least according to the Ditech and Valient websites, 
> but I can't seem to find anyone that actually sells them.  My hope was 
> that some of the other integrators or suppliers on this list might have found 
> a current product that fills this need.

You've identified the more common gear, however in my experience they prefer to deal with larger scale implementors/volume purchasers... Ideally, as others will no doubt suggest, a well performing g.168 software echo canceller needs to be developed for Asterisk. You tend not to see smaller scale (24B) external echo cancellers these days as most other systems (Cisco, Avaya etc. etc.) already integrate these chipsets or some variation thereof directly into their products.

Permanently 'fixing' zaptel echo is a major, major issue for the continued adoption of Asterisk in corporate environments. Technology demo projects start to look a little odd when you've got to drop a couple of thousand on a hardware echo canceller just to make it useable.

>  Is everyone just using the ancient Tellabs stuff?

Only cheap bastards like me who're trying to hedge their bets until something better than zaptel mec2 is released.
:-)