VidChat? Plz?

[Azhrei]

Here is what will happen,

• Client program will send out 100k/s as a multicast on VPN network
• VPN network stack will see this multicast, look at the end point addresses and say oh crud I cant reach them via multicast as they are all on different subnets so I can't send to the router and ask it to multicast any more than I could without a VPN.
• VPN network then sends 100k/s to each machine other machine individually, so you end up sending 400k/s for four other clients not just 100k/s.

Hmm. I think you're right.

The VPN creates another layer of IP addresses on top of IP, but I don't see any way to route packets more efficiently other than sending them multiple times. The reason is that the routers between clients will only work at Layer 3 (the IP layer) and not at the higher layer being created by the VPN.

Even those the IPOP protocol itself supports multicasting, I don't see any way to take advantage of that. The only reason for IPOP to support multicasting (that I can see now) is to support applications that require it. But there is no performance benefit to it.

Okay, everyone can ignore the last 2 pages of this thread. I took everyone down a path that turns out to be a dead end.

[Orchard]

Here is what will happen,

• Client program will send out 100k/s as a multicast on VPN network
• VPN network stack will see this multicast, look at the end point addresses and say oh crud I cant reach them via multicast as they are all on different subnets so I can't send to the router and ask it to multicast any more than I could without a VPN.
• VPN network then sends 100k/s to each machine other machine individually, so you end up sending 400k/s for four other clients not just 100k/s.

Hmm. I think you're right.

The VPN creates another layer of IP addresses on top of IP, but I don't see any way to route packets more efficiently other than sending them multiple times. The reason is that the routers between clients will only work at Layer 3 (the IP layer) and not at the higher layer being created by the VPN.

Even those the IPOP protocol itself supports multicasting, I don't see any way to take advantage of that. The only reason for IPOP to support multicasting (that I can see now) is to support applications that require it. But there is no performance benefit to it.

Okay, everyone can ignore the last 2 pages of this thread. I took everyone down a path that turns out to be a dead end.

Jerk.

It's really too bad though. I guess the REAL solution is to make sure everyone has 12 MB up AND down connections and go from there.

[BigO]

Jerk. It's really too bad though. I guess the REAL solution is to make sure everyone has 12 MB up AND down connections and go from there.

Ooo, I like the sound of that. Count me in.

[Orchard]

Jerk. It's really too bad though. I guess the REAL solution is to make sure everyone has 12 MB up AND down connections and go from there.

Ooo, I like the sound of that. Count me in.

What? You want me to count you in as a jerk? Sure thing. I'm always down for adding pretty much everyone to my list of 'people that I think are jerks'.




Oh? You meant the bandwidth thing? Yeah well, we can ALL put that in our pipes and smoke it...cause it's not gonna happen in the USA any time soon, for the same reason we don't have solid public transit: POPULATION DENSITY vs. PER CAPITA INCOME VS. TAX RATES VS. DECENTRALIZED LIVING & WORKING SITUATIONS. Not all apply to both, but it's a MAJOR issue.

[Craig]

Even those the IPOP protocol itself supports multicasting, I don't see any way to take advantage of that. The only reason for IPOP to support multicasting (that I can see now) is to support applications that require it. But there is no performance benefit to it.

As an aside, there are circumstances where multcasting support in a VPN is a good thing. One is service discovery where the data volume is low so it doesn't matter if you send it out to everyone on a VPN. The other is when VPNs are used to connect networks and not just machines.
So

Code: Select all

   Comp. A       \                                                  /   Comp. D
   Comp. B      ------ VPN end point <-----------> VPN end point -----  Comp. E
   Comp. C       /                                                  \   Comp. F

In such a setup you can configure your VPN so that everyone on Computers can hold a video conference or some other thing that uses multicasting, and the data only gets sent once through the VPN tunnel but delivered to all the computers on the other side.

Its not going to help you with your role playing group unless you can organise to meet in a couple of locations.

[RPMiller]

I'm surprised no one has mentioned WebEx. Take a look at their service and the way it works. I think that is the only way to get what you are after short of using a hardware solution. I use WebEx regularly at work for training my companies employees. It has voice, video and software sharing and is a web-based solution. The downside of course is that it isn't free, but I wonder if that technology is the best approach to take. Essentially MapTool is already establishing the connection between all the clients itself so that is the first part, the second is to compress the data streams with a codec that will provide a good balance of quality and compression, and then let the connection deal with the packet frames themselves.