Dreamcast-Talk.com

Right now there are a bunch of 3com superstack II RAS servers on ebay dirt cheap. Properly configured these should give true 56k dialup speeds to the DC.

I have one on the way (paid $20) and will update with the results.

interesting... keep us updated please.

Well, after a little more research, the only way to get 56K speeds to the Dreamcast is to use the RAS server with an ISDN simulator and terminal adapter. The ISDN simulator is the sticking point because they are a little out of my budget for this project.

I'm learning a lot about outdated networking and telephony though

I should still be able to get this working at 33.6K speeds, which should still be more than enough for DC online games. The main thing affecting online performance is latency, not data per second.

The DC games were designed for slow dial-up. Not everyone was able to connect at 56K back in the dial-up days and the usual fall-back speed was 33.6 or 28.8K so I'm sure the developers kept that in mind.

I'll keep plugging away at this...

With a v.92 modem you should be able to do 48k down/33.6k up theoretically.

brourke228 wrote:With a v.92 modem you should be able to do 48k down/33.6k up theoretically.

Both modems would have to negotiate a V.92 connection. The Dreamcast modem is only V.90 capable so it would never happen. With a V.92 modem, once the two negotiate V.90 , the V.92 modem will go into 33.6K (analog) upload mode.

I've been looking and, to my knowledge, you can't force a V.92 modem to upload at 48K.

To get speeds greater than 33.6K you need a digital (ie ISDN) modem uploading to the Dreamcast. Everything above 33.6K is done with PCM (aka digitally).

Here is the best explanation of V.90 56K I've found:

56k (Determined February 1998) refers to procedures between a “digital modem” and an “analog modem”. The analog modem, which may be connected to the PSTN through either an analog or digital interface, transmits V.34 signals and receives G.711 PCM signals. The digital modem, which is connected to the PSTN through a digital interface, transmits G.711 PCM signals and receives V.34 signals.

Source:http://www.vocal.com/data-modem/56k-modem/

The "digital interface" refers to ISDN in most cases. V.34 is analog 33.6K.

Because a V.92 modem has to conform to the rules of an analog modem, it can't act as a digital modem.

The faster upload of the V.92 standard may also degrade downstream performance, but since a) most Dreamcasts have at best a V.90 modem and b) Dreamcast games were all designed to fit within the constraints of the PAL 33K modems, the capabilities of V.92 don't matter.

Aleron Ives wrote:Dreamcast games were all designed to fit within the constraints of the PAL 33K modems, the capabilities of V.92 don't matter.

A very true point.

Also, for online games, players are uploading information to other Dreamcasts over the internet. Since the Dreamcast has a V.90 modem that speed is 33.6K max. It wouldn't matter then if you could receive at 56K because the fastest anything would be sent to you is 33.6K

I was more intrigued with having the ability to max out the Dreamcast's connection speed than for any practical benefits there might be.

I'm hoping that with this setup, though, I'll be able to achieve the lowest amount of latency possible.

SEGA RPG FAN wrote:I was more intrigued with having the ability to max out the Dreamcast's connection speed than for any practical benefits there might be.

That ability exists. It's called a broadband adapter.

But where's the fun in that? I need a challenge