Doubling or tripling dialup connections

[exequor]

I learned that someone can increase the dialup connection speed by using two modems, two phonelines and a special program that makes it work as one connection. Has anyone ever tried or heard of this?

 

[Evo]

I learned that someone can increase the dialup connection speed by using two modems, two phonelines and a special program that makes it work as one connection. Has anyone ever tried or heard of this?

I think I have, it's how ISDN works.

 

[graphic7]

I think I have, it's how ISDN works.

It's fairly similar, however, the key difference is that dialup modems are analog devices. ISDN is a digital, two channel (sometimes four), connection. The difference between a commericial connection, like a T1, and ISDN, is that a T1 uses many more channels (12 alone for data if I recall). So, a T1 and ISDN line are very similar technologies.

Bottom line, ISDN is still much better than a dialup connection using multiple modems.

Edit: On a sidenote, ISDN does not require you to have multiple "lines" per every 64kbps channel, unlike the dialup solution to having multiple "channels."

 

[Evo]

It's fairly similar, however, the key difference is that dialup modems are analog devices. ISDN is a digital, two channel (sometimes four), connection.

Yes, ISDN is digital. BRI (basic rate interface) utilizes two 64k lines. PRI (Primary Rate Interface) is provisioned over a T1 and delivers 23 (64k) channels ("B" bearer channels) and one signaling ("D" data channel).

The difference between a commericial connection, like a T1, and ISDN, is that a T1 uses many more channels (12 alone for data if I recall). So, a T1 and ISDN line are very similar technologies.

ISDN (Integrated Services Digital Network) is a type of service that can be delivered over either dial-up lines (2 line max) or T1. ISDN utilizes out of band signaling, which means that the 8k per channel (normally allocated for signalling ANI, DNIS, trouble shooting, etc...) can be used for traffic. A T1 in the telecom industry is just a 1.544Mb span, services like ISDN can be added to enhance functionality. An ISDN T1 normally has 23 B channels and 1 D channel, however, you can bond a small number of these together and designate 1 D channel to handle multiple T1's. The drawback to this is that if you lose the T1 with the D channel, you lose all T1's. This is where I would recommend a backup D channel.

Bottom line, ISDN is still much better than a dialup connection using multiple modems.

Absolutely.

Edit: On a sidenote, ISDN does not require you to have multiple "lines" per every 64kbps channel, unlike the dialup solution to having multiple "channels."

Actually, the telephone company does deliver one phone line per ISDN 64k channel (BRI), but the end user doesn't usually know this because we assign a fictitious telephone number, so they may not realize that they are getting two phone lines. Remember, BRI is only 128k max (two phone lines), the next jump is to provisioning ISDN over a T1 span (PRI).

 

[Anttech]

ISDN is a digital, two channel (sometimes four), ."

ISDN is digital. BRI (basic rate interface) utilizes two 64k lines

ISDN BRI is 3 channels not 2 or 4...
1 signaling
2 data/voice

T1 is ONLY applicable in USA. In Europe we use E1 as a standard, and it consists of 30 channels

the next jump is to provisioning ISDN over a T1 span (PRI).

Why do you say that? You can have as many ISDN BRI's as you like coupled together?

 

[Evo]

ISDN BRI is 3 channels not 2 or 4...
1 signaling
2 data/voice

Correct, 3 channels for BRI (2B+D) B1 & B2, for 128k (most common and the maximum BRI is delivered at) there would be 2 phone lines. There is 64k BRI which is 1B+D, not ordered very often anymore, but I still have clients using it. ISDN BRI isn't used much anymore, PRI T1 is used mainly for PBX feature functionality, not for data transmital much anymore, it's too cost prohibitive

the next jump is to provisioning ISDN over a T1 span (PRI).

Why do you say that? You can have as many ISDN BRI's as you like coupled together?

ISDN BRI is designed and delivered with 128k max. The next step up is ISDN PRI T1. You can purchase equipment that can "bond" multiple BRI's, but that doesn't change the BRI itself. Tying a bunch of water hoses together can deliver more water, but you are not changing the individual capacity of a single hose.

Also, for practical and financial reasons T1 is a better solution if you're needing significantly more bandwidth.

Edit: to clarify further, PRI bundling (NFAS) is done by the phone company and the circuits are engineered to have a single master D channel for multiple PRI's. Bonding of multiple BRI's is an equipment "fix" that the end user does himself on premise, the BRI circuits are not re-engineered into a "fat pipe".

 

[Anttech]

Also, for practical and financial reasons T1 is a better solution if you're needing significantly more bandwidth.

Not for teleco its not, if you only need approx 5 voice conversations at the same time you arent going to buy 1 T1/E1 you will typically buy 5 BRI and spread a DID range over them, so the person dialing in will only hit you on 1 number... and be round robined on the trunks...It is seamless

Large corporate companies still use T1/E1 because it is typically more rubust than other technologies. There are newer more robust technologies like MPLS but it's even more expensive than T1/EI (Do you have this state side yet?)... Dsl won't cut it when you have 2000 People trying to connect to WAN services

I understand what you are getting at now tho.. You can only provision BRI or PRI... You can't get delivered 1/2 a T1 or something

 

[Evo]

Not for teleco its not, if you only need approx 5 voice conversations at the same time you arent going to buy 1 T1/E1 you will typically buy 5 BRI and spread a DID range over them, so the person dialing in will only hit you on 1 number... and be round robined on the trunks...It is seamless

There is no way to give a short answer. Depends on what you are trying to do. You typically wouldn't want to use ISDN BRI for voice calls because you pay a lot more for ISDN usage than regular voice usage. But there are a lot of "ifs" it depends if local use is metered or flat rate. It depends on how your provider bills, if the call is sent out as ISDN or not. In this part of the US we will not provide DID's over ISDN BRI, it's not a tariffed offering, or if it is, it is so outrageously expensive, it's never sold. (I will look into the tariffs if i have time) (our non T1 offering for DID's is $100/mo per trunk, with a limit of 1 DID per trunk at a time, so if you want it to roll over to another trunk, it's another $100/mo) I actually have a client that has this on Plexar and I am moving him to a T1 for a huge savings.

Long distance ISDN usage is much more expensive than normal long distance, ballpark 47 cents per minute per channel as opposed to 2.5 cents per minute over regular long distance. Here in the US, the most common application for ISDN is videoconferencing.

Again, there are many flavors of "products" that utilize ISDN over T1. For example on a local T1 (used as a replacement for local phone lines), a company may need ISDN in order for them to receive ANI and utilize DNIS. It may be the only reason they need ISDN signaling. In this case BRI is not an option. They would not actually place ISDN calls from it and instead route over the regular PSTN. Costs change constantly, I price this stuff out every day.

Large corporate companies still use T1/E1 because it is typically more rubust than other technologies. There are newer more robust technologies like MPLS but it's even more expensive than T1/EI (Do you have this state side yet?)...

MPLS is utilized in WAN's here, it is not something ordered on an individual T1. The benefit is full meshing without multiple PVC's and QOS for voice/video/data. But it is over a network. MPLS is the big buzzword in networks, but traditional frame/ATM makes more sense $$ wise if your network is spoke & hub and you're not doing VOIP over the network. Voice over frame works fine and dialtone can be delivered as an FXS line to an old key set by adding a VIC to the router.

Dsl won't cut it when you have 2000 People trying to connect to WAN services

Yes, DSL is too unreliable and doesn't have the same performance SLA's (longer down time in the event of a repair issue)

You have the best understanding of telecom knowledge here (telecom has it's own weird world and unless you're inside of it, it's not easy to understand. Just because something can "work" doesn't mean that's how it's done, or allowed. I am constantly having to explain to clients the difference between what "can" work and how it can legally be engineered. Some services just are allowed. We stopped selling sub T1 rate private lines, I still have clients with them, but they can't order any new lines.

You are a network engineer for a telecom company? I'm in technical sales, which is why I know the tariffs (US regulatory nightmare) and costs involved.

 

[dduardo]

I'm not sure if windows has this but under Linux there is something called Bonding. This basically means you can take all your ethernet interfaces and make it look like one gaint pipe. I don't know if this works with dailup.

 

[Anttech]

(our non T1 offering for DID's is $100/mo per trunk, with a limit of 1 DID per trunk at a time, so if you want it to roll over to another trunk, it's another $100/mo) I actually have a client that has this on Plexar and I am moving him to a T1 for a huge savings.

wow... They cost us next to nothing here...! :-) In fact a building where we have a remote office gave us an ISDN 10, until we could get our trunks in...

but traditional frame/ATM makes more sense $$ wise if your network is spoke & hub and you're not doing VOIP over the network.

True... MPLS is nice tho, very fast, very good QoS, and 'can' deliver you savings in network hardware, but its just too pricey right now, unless you are investing in a furture proof converged network

Voice over frame works fine and dialtone can be delivered as an FXS line to an old key set by adding a VIC to the router.

Yes we use VIC's ints on Cisco 2600 to deliver PVN to remote offices, we've moved away from FR tho, although the uptime and Garanteed BW (CIR) was good there was to many savings to be had by moving over to a VPN/dsl spoke setup... We still use the PVN and it works ok, as we use Packetshapers on our WAN links to give some sort of QoS... Although its not end to end it is enough..

Yes I am Network Engineer, and I do a lot of Avaya/Cisco VoIP stuff nowadays also, but mainly data networks

 

[Evo]

I think we're hijacking the thread.

We do Cisco, Nortel & Avaya for phone systems, mostly Cisco for routers & switches, and some Adtran.

DID's are $10/mo for a block of 100 if it's on a T1, big difference, doing DID's off a T1 here are intentionally priced high so that people don't buy them.

 

[exequor]

Well since I can't get ISDN or DSL in my area (I guess if I could have, I would have done it already), is there someway that I can get some ISDN equipment and use it for a dialup connection? I only asked that question because I don't know if on the server's side this is possible/impossible.

 

[brewnog]

Well since I can't get ISDN or DSL in my area (I guess if I could have, I would have done it already), is there someway that I can get some ISDN equipment and use it for a dialup connection? I only asked that question because I don't know if on the server's side this is possible/impossible.

You shouldn't need the ISDN equipment. You can do it with two modems, and two normal phone lines. You just bridge the connections together in Windows (or whatever).

 

[Anttech]

You shouldn't need the ISDN equipment. You can do it with two modems, and two normal phone lines. You just bridge the connections together in Windows (or whatever).

The only way I can think you could do this would be to buy a router with 2 DDI (demand dailing ints) interfaces, and then 50/50 load balance across them...You would also need a static public IP address on the inside INT of your router... You could get this to work if you were willing to throw lots of money at it... But I don't think it is worth it

Perhaps on Linux, or more likely freeBSD (configured to route) you could do this with a dual homed box...

The problem I see to doing this on you PC is that every "session" you open (ie a www site) will have to be sent through only 1 interface on the PC so there won't be any visable difference between having 1 modem or 2 attached to you PC.

The reason why you can't switch between modems on the same session, is that www server you are connecting to will get confused when the tcp sequence numbers get out of sync and from different IP addresses which will happen. (AFAIK)...

 

[Anttech]

I think we're hijacking the thread.

hehe yep ;-)

 

[Evo]

I knew I'd read this somewhere, it's called multi-linking. The problem is that a lot of ISP's will not allow this.

HOW TO: Set Up Multiple-Device (Multilink) Dialing in Windows XP

SUMMARY
This article describes how to configure multiple-device dialing in Windows XP.

With Windows XP, you can use multiple modems to connect to your Internet service provider (ISP) to increase the total speed of your transfers. Multiple-device dialing (also known as Multilink PPP, modem aggregation, or Multilink) causes multiple physical links to be combined into one logical link. Typically, two or more ISDN lines or modem links are bundled together for greater bandwidth. You might use this feature if you do not have access to DSL or cable services.

http://support.microsoft.com/default.aspx?scid=kb;en-us;307849&sd=tech

 

[Anttech]

well... if your isp will allow 2 dial-ups to be linked to 1 ip address it will work, if not then I can't see how it would be of any use

Your ISP must support synchronization of multiple modems.

Thats what I was getting at in my last post... typically you get 1 IP address per dial up, not 1 across multiple dial ups

 

[Evo]

well... if your isp will allow 2 dial-ups to be linked to 1 ip address it will work, if not then I can't see how it would be of any use



Thats what I was getting at in my last post... typically you get 1 IP address per dial up, not 1 across multiple dial ups

Yes, your post was spot on...which is why you don't really see anyone doing this.