Re: Low latency IP direct connection over ISDN

On 2012-11-12 01:33, "Schürer IT Beratung -- Urs J. Schürer" wrote:
>> 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"
> 
> You may try to get one and hook up two SDSL modems, but at least here in
> Munich the Telekom does not sell those lines any longer.

Were these leased SDSL lines or as Patrick suggested "dry copper pairs"?

>> I want to connect two sites in Germany with minimal latency under low
>> bandwidth requirements.
> 
> Basically ISDN is a low latency network, that is why you do not
> recognize any echo as with VoIP calls. Depending on the distance and the
> network hubs in-between it should be well within a few ms, as long as
> your provider did not already switched it to an All-IP network which
> unfortunately is currently going on.

I have nothing against IP-based and packet-switched networks. If
implemented correctly (which is harder and more error-prone that simple
TDMA/WDM) they are as (or more) effective and failure-tolerant as (than)
previous (virtually) circuit-switched technology used in the
telecommunication sector (I don't want to open this debate on the
mailing list). My only problem is that I have a different ISPs at each
location (that I can't switch) and thus all traffic is routed to a
central internet exchange with respective latency. For this use case it
doesn't matter if it's IP, ATM or something else that transports the
data, the latency is inherent in the underlying topology (I can't tell
if (IP-based) routing and thus latency would be better if both locations
had the same ISP, but I guess that with two DSL lines Deutsche Telekom
latency wouldn't improve much (I could test this with two friends if
somebody is interested)).

Regards,
Matthias-Christian