Voip setup

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rush6432
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Voip setup

Postby rush6432 » Wed Jan 30, 2013 6:00 pm

Hey guys, ive been researching a little lately and found that it MIGHT be possibly to do a voip setup finally with the netlink..

Ive seen posts where users are reporting they are able to do about 40-50kb/sec over google voice with voip to a dialup internet connection..

If this is indeed true... then i dont see why we couldnt run netlink games through some sort of voip router and dial a direct person through google voice...

I may try to tackle this sometime as it will apply to other consoles that have modems as well and not just the saturn.

Rogue
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Re: Voip setup

Postby Rogue » Wed Jan 30, 2013 6:48 pm

Good luck with that. But voip is so bad, imo, that it will be impossible to handle a device designed for dial up.
The quality accepted for telecom business is really bad if one compare to analog line. Not bad like cell phones, though. Those are the worst...
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Warp2063
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Re: Voip setup

Postby Warp2063 » Wed Jan 30, 2013 9:20 pm

Bandwidth isn't the issue - it's the timing. You don't get synchronous connections on the internet. That 40-50kb/sec is an average, not an actual sustained transfer rate. You could get that 40-50 kilobits during any number of random moments during that second, or maybe you had two seconds of nothing, and in the next three you got 200-250 kilobits, and it averaged out to 40-50kb/sec. While accessing the internet, you have lots of gaps in your connection - some lasting only tiny fractions of seconds, and others lasting much longer. If you're just transferring a file, there's no problem - you just need all the bits. Timing isn't important.

Multiplayer games that require constant updates on each of the players are different. Those gaps create problems. Say you're playing a high-speed fighting game. Ryu throws a punch at Ken. However, there's a bit of lag (latency) in the connection, and Ryu hasn't heard back from Ken. Ryu's machine is now unsure of what to do. Did Ken dodge? Should a hit be registered and HP be decreased? Did Ken throw a low kick at that moment? Should Ryu be taking damage instead? Does Ken even know that Ryu threw a punch? This is a synchronization issue.

With complex algorithms to make predictions about what happened, what happened during the gaps can be fudged in certain cases, as long as the delay until the next update is sufficiently small. However, the longer the gap, the bigger the problem. That single example from my averages earlier? Two seconds would be an eternity during a fighting game. Those two seconds could spell the difference between victory or defeat.

The Saturn doesn't have complex algorithms for handling latency - those didn't start popping up very often until a few years later on PCs. Instead, they relied on the relative rock-steadiness of a phone line to transmit data with high levels of synchronization. Because it was a more-or-less direct connection, without data being bounced around across dozens of servers all over the internet, you didn't end up with lots of little delays in your connection. Sure, sometimes data would be lost, corrupted, or delayed. The NetLink's answer to that? Pause the game until the modems could confirm that they had resynchronized. Because phone lines were so reliable, usually these resynchronization exchanges would take only fractions of seconds too small for people to really notice. If there were too many delays or the delays were too long to maintain good synchronization, it was programmed to terminate the link.

VOIP devices send their data over the internet. Instead of a dedicated line, you have many servers that are constantly relaying information to one another. The VOIP device is programmed to handle the little delays accrued when relaying data from server to server over the internet. Some of the packets get lost or take a longer route to get to their destination? Due to the much higher bandwidths available today, you can simply send more bits in a sliver of time than you could before. So, during that first fraction of a second, the packets containing the audio data for part of a spoken word happen to be lost on the internet. So, the VOIP device resends that data, along with the data for the next sliver of audio data. This time, both pieces make it, and the other VOIP device decodes it and plays it back. To the human ear, that delay was so short that it wasn't noticeable.

To a machine, that time sliver could last many milliseconds. To a dial-up modem, sending digital data as audio, that gap would throw off its synchronization, and the two modems would have to renegotiate their connection and resume sending data. In the case of the NetLink, this can cause those little delays you get while playing a NetLink game.

By proposing adding VOIP devices into your circuit, you're adding the slowdowns and hiccups on the internet to your NetLink game. Why aren't there problems with using the NetLink PlanetWeb browser over VOIP? It just needs the bits. It doesn't care about when it gets them. It can afford to perform the synchronization negotiations, because it's in no hurry to get the files that make up a web page. A game can't wait.

If you manage to find a VOIP service and a steady enough internet connection to the other person's VOIP device that those delays would be minimized and much NetLink data wouldn't be lost by whatever codec compresses the audio data for the VOIP device to transmit/receive? The NetLink wouldn't have to perform many synchronization negotiations, and you could theoretically play games over your VOIP service. But you're facing a lot of interference these days. Sharing network connections in your home with other connected devices, internet providers throttling connections, internet providers sharing bandwidth for an area with other subscribers, high loads on servers that will be relaying your signals over the internet, electromagnetic interference... these and plenty of other things are all going to be working against you. You could get lucky. But you might not. It's not impossible that this could work - but there's so many things interfering that it's not likely.
I have my Saturns, I have some of my games, I have a RasPi. Gotta put all this stuff together!

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SEGA RPG FAN
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Re: Voip setup

Postby SEGA RPG FAN » Sun Apr 06, 2014 9:42 pm

The best bet for using the netlink with VoIP is using hardware and protocols that keep things synchronized.

ISDN over IP is designed to make sure that the and far end devices are in synch and nothing arrives out of order (as things can do in a TCP/IP environment). Of course this hardware is not cheap.

Many Cisco/Linksys devices allow a modem passthrough mode by entering a dial prefix (*90 if I remember right). This is worth looking into because the idea is much the same as ISDN over IP, but a little less strict and the devices that support it are relatively cheap.

Just my two cents. I don't have any VoIP hardware to test with at the moment but hopefully someone who does, can get some ideas.

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Re: Voip setup

Postby Warp2063 » Mon Apr 07, 2014 1:54 pm

Maybe there is hardware out there that will help, but the internet and the number of hops from point to point will add latency - latency that tends to disagree with the NetLink. Packets arriving out of order, while irritating and a slowdown, isn't a huge issue, because they're reassembled in the correct order once they've arrived.
I have my Saturns, I have some of my games, I have a RasPi. Gotta put all this stuff together!

Xiden
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Re: Voip setup

Postby Xiden » Sat Feb 18, 2017 3:55 pm

Me and SEGARPGFAN have officially got netlink workng over voip :) You dont even need a voip provider just two two Unlocked Linksys SPA1001 FXS VoIP Phone Adapters
Needs to be configured properly but ill post a guide soon

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Xranger60
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Re: Voip setup

Postby Xranger60 » Sat Feb 18, 2017 3:57 pm

So how's the lag? The problem has always been that the extra lag can muck up the experience and lead to desyncs. Is it playable?
Willing to play Bomberman, Duke Nukem 3d, Virtual On, Sega Rally. Send me a PM.

Xiden
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Re: Voip setup

Postby Xiden » Sat Feb 18, 2017 4:51 pm

Sega rally is virtually lag free. Saturn bomberman has a little lag but it very playable and still fun

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SEGA RPG FAN
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Re: Voip setup

Postby SEGA RPG FAN » Sat Feb 18, 2017 7:18 pm

Bomberman has like a split second hitch every second or so. It's a very regular pattern so you get used to it. It's definitely playable.

Xiden
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Re: Voip setup

Postby Xiden » Sun Feb 19, 2017 4:29 pm


Krazystyle
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Re: Voip setup

Postby Krazystyle » Mon Feb 20, 2017 2:37 pm

Holy crap! This is awesome!

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SEGA RPG FAN
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Re: Voip setup

Postby SEGA RPG FAN » Thu Mar 09, 2017 7:36 pm

Played a couple rounds of Sega Rally and Daytona last night via VOIP. My opponent recorded it: viewtopic.php?f=1&t=973#p8853
Gives you a sense of the quality of the connection.


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