Re: 28.8 Upgrade

Christopher M Sedore (cmsedore@interrel4.case.syr.edu)
Tue, 6 Jun 1995 07:55:09 -0400 (EDT)


On Mon, 5 Jun 1995, Michael Sattler wrote:

> >During my research I investigated a variety of dial up telephone line
> >connections using both 14.4 and 28.8 SLIP and PPP connections. My research
> >showed that PPP was more reliable,
>
> I must strenuously disagree. Both SLIP and PPP are equally reliable for
> transport, it depends upon the software you're choosing to make the
> connection.

Agreed.

>
> >and 28.8 provides passible performance,
> >when used in conjunction with Talk Window. A lot also has to do with the
> >quality of line that your service provider gives you access to the net
> >with, and this quality usually depends on how much you want to pay.
>
> Disagree. The quality of the line you get with a modem has nothing to do
> with your provider, but with your local phone company.

Both, wouldn't you say? If your provider has a 56k link and 15 people
competing for it, that line quality (perhaps better stated "capacity"), in
addition to your phone line, will be a major determining factor. Same
goes for a net provider who has poor connectivity on his providers
net-I've seen T1s into the net that only allowed 5-7KB/s to the NSF backbone
because the net provider's backbone net was severely oversubscribed.

> Something that's been unmentioned here is that PPP takes an extra five
> percent bandwidth away from you for it to be able to support multiple
> protocols. SLIP only does IP. That 5% should be enough for modem users to
> demand SLIP in bandwidth-intensive situations such as CU-SeeMe.

I'd like to see how you come to those calculations. The PPP difference
should be something like 5 bytes per packet more than SLIP, which works
out to little more than .5% on a 1000 byte mtu or 1.9% on a 256 byte mtu.

-Chris