Re: Low latency IP direct connection over ISDN

On 2012-11-11 22:58, Patrick Lists wrote:
> On 11/11/2012 07:20 PM, Matthias-Christian Ott wrote:
>> Hi,
>>
>> I want to connect two sites in Germany with minimal latency under low
>> bandwidth requirements. Both sides have numbers with the same area code.
>>
>> It seems that all data on ADSL2+ lines is routed to a central exchange
>> several hundred kilometres away and thus latency is more than 60 ms (one
>> site is far away from the DSLAM and only has a 384 Kbit/s connection).
>> Can latency be improved via ISDN (I've read contradicting statements
>> about this)? My theory is that a direct ISDN connection (with itund)
>> would be routed within the same regional area and not sent to a central
>> internet exchange.
> 
> No idea if ISDN would result in less latency. Never heard of that before.
> 
> Eons ago the trick I used with an ISP to avoid going through a far away
> main Central Office (CO) which aggregated traffic from several closer
> CO's was ordering something called a "dry copper pair" which would
> transparently connect between my site and the ISP via the closest
> intermediary Central Office(s) and avoiding the far away Central Office.
> The telco basically created one long copper pair going from my site to
> the ISP's colo without going through any equipment. At the ISP the
> copper pair was hooked up to a port on (iirc) an Ascend MaxTNT and on my
> side a Telindus DSL modem was used. Result: a stable 2Mbit/s link with
> low latency at a cost of €50/month.
> 
> Obviously telco's don't like these kind of deals. They would rather sell
> you an expensive fiber link hooking up to some metro SDH/SONET ring. So
> make sure you say it's for an alarm system or some kind of M2M
> monitoring thingy. Don't tell them you need a business DSL link with
> less latency. I'm not even sure if telco's still offer "dry copper
> pairs" so you may want to ask around.

I've read that Deutsche Telekom doesn't offer leased analogue lines
anymore and cancelled existing contracts.

Regards,
Matthias-Christian