!#*****Dialup ISP Question****#!

AFB

Lifer
Jan 10, 2004
10,718
3
0
How do they work in general? How do they get all those calls through one phone line ?
 
 

JackMDS

Elite Member
Super Moderator
Oct 25, 1999
29,544
421
126
It is not one telephone line it is one Number.

Most businesses have One Number and a lot of lines. It is nothing to do with ISP it is simple phone technology.
 

Devistater

Diamond Member
Sep 9, 2001
3,180
0
0
Originally posted by: JackMDS
It is not one telephone line it is one Number.
Most businesses have One Number and a lot of lines. It is nothing to do with ISP it is simple phone technology.
Yep, they have one public phone number that "forwards" to a free line. Or something like that. In busy towns they could have hundreds or more lines connected to one phone number. I dont know the technical details, but they wouldn't want to have differant phone numbers to call for each line, too confusing. And then when you hang up they wouldn't be able to give your line to someone else. Very ineffecient. So they group them all together into 1 number. Similar reasoning for a pool of IP addresses they give out.
 

bgroff

Member
Jun 18, 2003
198
0
0
Heh, it could be one line depending upon what equipment the ISP is using and what the telco is capable of delivering. Nothing like a channelized DS3 full of voice channels... :p
 

spidey07

No Lifer
Aug 4, 2000
65,469
5
76
DS1 - 23 "phone lines" on a single cable usually attached to a "dial server" that uses digital modems for each of those 23 phone lines.

DS3 - 28 (i think, been a while) DS1s on two coaxial cables attached to a dial server, digital modems, etc.

One phone number is assigned to a "hunt group" so that an incoming call to that phone number follows a non-busy "phone line". Now remember that phone line is kinda virtual (reference TDM thread going on)

call comes in, digital modem answers, start PPP/authentication, got IP address info, rock-n-roll.

One cool thing is you can have literally 1000s of digital modems all in one rack.
 

bgroff

Member
Jun 18, 2003
198
0
0
Originally posted by: spidey07
DS1 - 23 "phone lines" on a single cable usually attached to a "dial server" that uses digital modems for each of those 23 phone lines.

DS3 - 28 (i think, been a while) DS1s on two coaxial cables attached to a dial server, digital modems, etc.

Yep, its 28 DS-1s in a DS-3. And you can get all 24 channels available for use if you don't use PRIs for incoming calls (RBS isn't that bad if you don't have incoming ISDN calls...) or you can share the D channel among PRIs with NFAS (Non-Facility Associated Signalling). More neat telco tricks...