Re: [SLUG] multi-link PPP
On Mon, 21 Aug 2000, Dave Fitch wrote:
> > As for ISDN being easier - the investment in TE is probably equal to
> > dialups,
>
> I think it's cheaper, but of more benefit to the ISP is no modem
> incompatibility problems etc, it cuts out the A-D conversions,
> a straight digital pipe you run PPP over.
I doubt it'd be cheaper - as Umar pointed out, similar equiptment is used
- and I'd actually think it would be more expensive, given what I've seen
of Cisco's products {for example, a 3640 with a PRI and 30 modems for
accepting "dial up" connections as opposed to a 2620 with a PRI for just
accepting "data" calls. The distinction being that to accept calls from
POTS services using 65/33k6 modems, there must still be a modem involved,
whereas to accept a straight ISDN data call there doesn't have to be.
> > byt tyhe provision for abuse in downloading is _much_ higher,
> > given that ISDN connections are usually permanent, and dialups can be
> > dropped off if they're abusing.
>
> well I've heard that argument before too but never really agreed
> with it. If the ISP's pricing model is done properly there's no
> problem. Eg. charge by the Mb, or impose a monthly download limit
> etc. I agree that given the speed (or lack thereof) of modem
> connections it seems "safer" but (a) 64k ISDN not that much faster
> and (b) with the growth of cable and xDSL and others, ISPs will have
> to get used to it sooner or later.
How many ISP's do it properly, though? :-) "Flat rate" access is the
commonest claim - and only because they know how much can be sucked down a
56k modem in a month, and gamble on not everyone actually doing it.
As for 64k not being much faster - well, 64k full duplex would be about
20k faster downstream, and at least 30k faster upstream, for me. My best
modem connections are 46k/31k6 - 64k full duplex would be a blessing.
> At one stage I considered "casual" dialup ISDN rather than modem
> (probably 128K) but it's really telstra's pricing that puts the
> kybosh on that, not the ISP. The only vaguely cost effective
> ISDN (IMO) is the "onramp home highway" service then run "data
> over voice" to get the 22/25c untimed connections whilst still
> getting more or less ISDN speeds but that requires a cooperative
> ISP willing to do some "special" configuration at their end.
No argument on that one - Telstra has priced ISDN out of the market for
most people. When you compare the prices in the USA to what we pay.
{sigh}.
DaZZa
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Re: [SLUG] multi-link PPP
On Mon, 21 Aug 2000, Umar Goldeli wrote:
> > dialups, byt tyhe provision for abuse in downloading is _much_ higher,
> > given that ISDN connections are usually permanent, and dialups can be
> > dropped off if they're abusing.
>
> Most ISP's nowadays use the same gear for their normal dialups as well as
> their ISDN connections - in fact - if they support 56k - they most
> definitely already have the gear for supporting isdn.
Not necessarily - but possibly. :)
> The term "permanent" with respects to isdn - is not really correct - it's
> always semi-perm - due to the nature of isdn - i.e. a call must be made -
> i.e. it's not "hardwired" like services such as DDS Fastway or a Megalink
> for example.
Semantics - effectively, even a semi-permanent ISDN call is closer to
permanent than a POTS dialup. Yes, it's a circuit switched connection -
but it's designed to be "permanently" connected, whereas POTS is not.
> Hence, the procedure for disconnecting an isdn call is exactly the same as
> for bumping a normal dialin user.
I was actually referring to the fact that MOST {happy, Dave? :-)} ISP's
use ISDN dialups for their "permanent" commections as opposed to their
dialups, and don't generally bounce them for being online over a session
limit or some such like - again, comparing to "normal" dial ups.
> (btw - I'm talking about modern integrated access platforms like cisco
> 5260's, Ericsson Tigri etc etc.. not the old fashioned, grab a TA220 and
> stick it into a 2501 method - but even so, the above still applies :)
What's wrong with a TA and a 2500? :) Hell, what's wrong with an NT1 and a
2503? :-)
DaZZa
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Re: [SLUG] multi-link PPP
> But if you, as an ISP, were only going to support customers > connecting via ISDN you'd buy a simpler/cheaper access server. > Those cisco ones with 60 x 56k modems cost a fortune compared > to say a 25xx/26xx router. Bingo. (just maybe not the 25xx bit :) But yes, for example, you can get a *huge* 11-slot Tigris chassis loaded with about 1000 B channels worth of ISDN controllers for about the same price as the same chassis loaded with only a handful of DSP cards. //umar. -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://slug.org.au/lists/listinfo/slug
Re: [SLUG] multi-link PPP
Umar Goldeli <[EMAIL PROTECTED]> > > As for ISDN being easier - the investment in TE is probably equal to > > dialups, byt tyhe provision for abuse in downloading is _much_ higher, > > given that ISDN connections are usually permanent, and dialups can be > > dropped off if they're abusing. > > Most ISP's nowadays use the same gear for their normal dialups as well as > their ISDN connections - in fact - if they support 56k - they most > definitely already have the gear for supporting isdn. it means they already have ISDN lines coming in so you just get a port without a 56k modem on it (I would imagine). But if you, as an ISP, were only going to support customers connecting via ISDN you'd buy a simpler/cheaper access server. Those cisco ones with 60 x 56k modems cost a fortune compared to say a 25xx/26xx router. Dave. -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://slug.org.au/lists/listinfo/slug
Re: [SLUG] multi-link PPP
On Mon, Aug 21, 2000 at 11:43:15AM +1000, Umar Goldeli wrote: > > As for ISDN being easier - the investment in TE is probably equal to > > dialups, byt tyhe provision for abuse in downloading is _much_ higher, > > given that ISDN connections are usually permanent, and dialups can be > > dropped off if they're abusing. > > Most ISP's nowadays use the same gear for their normal dialups as well as > their ISDN connections - in fact - if they support 56k - they most > definitely already have the gear for supporting isdn. > Acually the ISDN always works out cheaper for the ISP. Since the ISDN call is purely digital you don't need to buy DSP cards for your access servers. Which on Ciscos work out to about $20k per 120 channels. Assuming people are paying by the meg than ISDN is always a better deal for the ISP. By the hour it's not since you can pull a bit more down over ISDN than modem. -- John -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://slug.org.au/lists/listinfo/slug
Re: [SLUG] multi-link PPP
DaZZa <[EMAIL PROTECTED]>
> On Mon, 21 Aug 2000, Dave Fitch wrote:
> > > Add to this the fact that ISP's charge _much_ more for a 64k ISDN account
> > > {$500 a month, roughly?} than they do for two dialup accounts {2 x $50 a
> > > month?}, and ISDN comes out behind.
> >
> > make that "most ISPs". There are some that charge the same $ per
> > hour charge or $ per Mb regardless of whether it's PSTN or ISDN
> > you're connecting via (eg. www.albury.net.au). In many ways a
> > customer using ISDN is easier and cheaper for the ISP I would've
> > thought.
>
> OK, I accept the qualification. :-)
>
> As for ISDN being easier - the investment in TE is probably equal to
> dialups,
I think it's cheaper, but of more benefit to the ISP is no modem
incompatibility problems etc, it cuts out the A-D conversions,
a straight digital pipe you run PPP over.
> byt tyhe provision for abuse in downloading is _much_ higher,
> given that ISDN connections are usually permanent, and dialups can be
> dropped off if they're abusing.
well I've heard that argument before too but never really agreed
with it. If the ISP's pricing model is done properly there's no
problem. Eg. charge by the Mb, or impose a monthly download limit
etc. I agree that given the speed (or lack thereof) of modem
connections it seems "safer" but (a) 64k ISDN not that much faster
and (b) with the growth of cable and xDSL and others, ISPs will have
to get used to it sooner or later.
At one stage I considered "casual" dialup ISDN rather than modem
(probably 128K) but it's really telstra's pricing that puts the
kybosh on that, not the ISP. The only vaguely cost effective
ISDN (IMO) is the "onramp home highway" service then run "data
over voice" to get the 22/25c untimed connections whilst still
getting more or less ISDN speeds but that requires a cooperative
ISP willing to do some "special" configuration at their end.
Dave.
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Re: [SLUG] multi-link PPP
> As for ISDN being easier - the investment in TE is probably equal to > dialups, byt tyhe provision for abuse in downloading is _much_ higher, > given that ISDN connections are usually permanent, and dialups can be > dropped off if they're abusing. Most ISP's nowadays use the same gear for their normal dialups as well as their ISDN connections - in fact - if they support 56k - they most definitely already have the gear for supporting isdn. The term "permanent" with respects to isdn - is not really correct - it's always semi-perm - due to the nature of isdn - i.e. a call must be made - i.e. it's not "hardwired" like services such as DDS Fastway or a Megalink for example. Hence, the procedure for disconnecting an isdn call is exactly the same as for bumping a normal dialin user. (btw - I'm talking about modern integrated access platforms like cisco 5260's, Ericsson Tigri etc etc.. not the old fashioned, grab a TA220 and stick it into a 2501 method - but even so, the above still applies :) //umar. -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://slug.org.au/lists/listinfo/slug
Re: [SLUG] multi-link PPP
On Mon, 21 Aug 2000, Dave Fitch wrote:
> > Add to this the fact that ISP's charge _much_ more for a 64k ISDN account
> > {$500 a month, roughly?} than they do for two dialup accounts {2 x $50 a
> > month?}, and ISDN comes out behind.
>
> make that "most ISPs". There are some that charge the same $ per
> hour charge or $ per Mb regardless of whether it's PSTN or ISDN
> you're connecting via (eg. www.albury.net.au). In many ways a
> customer using ISDN is easier and cheaper for the ISP I would've
> thought.
OK, I accept the qualification. :-)
As for ISDN being easier - the investment in TE is probably equal to
dialups, byt tyhe provision for abuse in downloading is _much_ higher,
given that ISDN connections are usually permanent, and dialups can be
dropped off if they're abusing.
DaZZa
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Re: [SLUG] multi-link PPP
DaZZa <[EMAIL PROTECTED]>
> Add to this the fact that ISP's charge _much_ more for a 64k ISDN account
> {$500 a month, roughly?} than they do for two dialup accounts {2 x $50 a
> month?}, and ISDN comes out behind.
make that "most ISPs". There are some that charge the same $ per
hour charge or $ per Mb regardless of whether it's PSTN or ISDN
you're connecting via (eg. www.albury.net.au). In many ways a
customer using ISDN is easier and cheaper for the ISP I would've
thought.
Dave.
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Re: [SLUG] multi-link PPP
On Sat, 19 Aug 2000, Roland Turner wrote:
> - Have you actually costed an ISDN solution? You may find that, unless
> you use particularly cheap modems (which really will perform badly), the
> ISDN solution may not be as expensive as you are expecting.
Depends over what kind of time period you're talking.
The sheer cost of running a semi-permanent ISDN connection {$280, or
thereabouts, a month} compared to the savings of dialup calls {2, 3 drop
outs a week? Call it $4 a month per line} makes ISDN a whole lot more
expensive. ISDN also costs more to setup {ISDN router - $500 minimum -
ISDN card not much less - two modems? Maybe $300 each, ISDN installation
is also more expensive}. All up, setting up an ISDN link could cost as
much as $800, plus $280 for the first month's worth of calls/connect
charges.
Add to this the fact that ISP's charge _much_ more for a 64k ISDN account
{$500 a month, roughly?} than they do for two dialup accounts {2 x $50 a
month?}, and ISDN comes out behind.
However, the two big advantages you quoted make ISDN attractive if you're
serious - not to mention the fact that ISDN tends to have less degradation
from bad lines etc.
DaZZa
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Re: [SLUG] multi-link PPP
Roland Turner wrote:
>
> "Marshall, Joshua" wrote:
>
> > Will the connection actually run at 66k with two 33k modem links? What
> > sort of reliability might I expect, for example, what happens if one link
> > dies - does it revert to 33k until the other link re-establishes?
>
> Yes, but:
>
> - You'll have (much) higher latency using modems than using ISDN (170ms
> vs. <20ms).
Yes but, Costing of Multi-link PPP is wonderfully better.
Total cost is PER LINK is
Setup = two modems and two line installations @ $173???
Onoing $40/month (? what is business now per month) and worst case 1
call (25c/day)
Actually, the lines DO NOT have to be business lines.
No data charges, no time charges.
I serve WWW and email across a dial up link. The only people who have
trouble with the latency are spammers.
...snip...
> - Have you actually costed an ISDN solution?
Yes, repeatedly over more than 10 years.
> You may find that, unless
> you use particularly cheap modems (which really will perform badly), the
> ISDN solution may not be as expensive as you are expecting.
You will find that the ISDN link will bleed you dry unless you are
going to make a MOTZA each month.
Actually, badly tuned modems will perform badly, no matter what the
brand.
Two 33K modems will get close to 66K depending on lines, modem tuning
and EQL/?.
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Re: [SLUG] multi-link PPP
"Marshall, Joshua" wrote: > Will the connection actually run at 66k with two 33k modem links? What > sort of reliability might I expect, for example, what happens if one link > dies - does it revert to 33k until the other link re-establishes? Yes, but: - You'll have (much) higher latency using modems than using ISDN (170ms vs. <20ms). - Multi-link PPP will degrade correctly as individual links drop out. Given that you are talking about using linux-2.2 (i.e. EQL) though, I really don't know. - Have you actually costed an ISDN solution? You may find that, unless you use particularly cheap modems (which really will perform badly), the ISDN solution may not be as expensive as you are expecting. - Raz -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://slug.org.au/lists/listinfo/slug
Re: [SLUG] multi-link PPP
> Multilink PPP is only supported by the 2.4 kernels, however, if you've got a > Linux machine or a Livingstone Portmaster on the the other end, you can use > EQL, which is essentially the same. I'm installing both ends so it'll be a Linux machine latest 2.2 kernel. > Remember that you advantages lie in paying for just the phonelines required, > and nothing more. Will the connection actually run at 66k with two 33k modem links? What sort of reliability might I expect, for example, what happens if one link dies does it revert to 33k until the other link re-establishes? Josh. -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://slug.org.au/lists/listinfo/slug
Re: [SLUG] multi-link PPP
> Marshall, Joshua wrote: > > Before I start working on it I'd like to know whether I am just wasting > my time and just go for 64k ISDN or something? Multilink PPP is only supported by the 2.4 kernels, however, if you've got a Linux machine or a Livingstone Portmaster on the the other end, you can use EQL, which is essentially the same. There are a couple of applications that give your Linux 2.2 machine MPPP capabilities, but the ones I've seen are pretty gross, and lack all concept of the way Linux does things. If you can, go for EQL, otherwise wait or try something else. Remember that you advantages lie in paying for just the phonelines required, and nothing more. - Jeff -- [EMAIL PROTECTED] --- http://linux.conf.au/ -- Ye shall be cursed to fall in love so easily, and yet be so cold of heart as never to express it. -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://slug.org.au/lists/listinfo/slug
[SLUG] multi-link PPP
Has anyone had any experience with Multi-link PPP connections? I'm considering using it for two offices for a medium-speed (66kbps each way?) permanent link. Before I start working on it I'd like to know whether I am just wasting my time and just go for 64k ISDN or something? Cheers, Josh. -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://slug.org.au/lists/listinfo/slug
