Hello all, I was wondering what you all think is the maximum bandwidth per second that a game should take up. (and recommended) For several types of network: 1. Dial Up Connection 2. Cable Connection 3. 10/100mbs LAN Any opinions? --Josh

1. 4k/s (includes up and down) will allow 33.6k or better users as long as they have a solid connection.
2. less than 10k/s up (many broadband connections are limited to 12 or 16k/s upload speeds) anything up to about 30k/s download (the slowest broadband download speeds i know of is 32k/s)
3. Depends how many players you plan to support. Because LAN''s are broadcast networks, you have to directly scale the bandwidth consumption to the number of players.

Ok then...Say 100 peeps on the LAN?

Is there a function that allows a message from the server to be adressed to Multiple IP addresses? That would save on Bandwidth for particular messages that I would need to send...


[edited by - JoshG on September 27, 2002 3:35:59 AM]

Sounds like multicasting. I don''t think every ISP supports it so it may not be a viable option.

---

Helpful links:
How To Ask Questions The Smart Way | Google can help with your question | Search MSDN for help with standard C or Windows functions

If you''re talking about a LAN, you just send it to the broadcast address, which is (if i remember corectly) *.*.*.255, where the stars are your normal numbers of your LAN''s IP range. I think there may also be a winsock #define for this (INADDR_BROADCAST or something??). A message sent to the broadcast address is recognised by every computer on the LAN, as long as they have the appropriate port open to listen etc. I think broadcasting is also only available to UDP datagrams, and not TCP streams.

If you have 100 players on a 100Mbit LAN, you could theoretically give each player a bandwidth of 125k/s each as long as there is no other traffic on the network. for a 10Mbit lan, just divide by 10 and you can give each player about 12.5k/s each. These calculations assume that all 100 players are on the same hub, and assumes you aren''t using switches or routers between any of the computers on the LAN which would reduce traffic.

Just extending from annoymous'' post,

whatever your netmask is i.e. 255.255.255.0 (default for 192.168.0.* networks) the multicast address is simply all the remaining bits as on. (i.e. 255 = 11111111) so your multcast for that network is 192.168.0.255

About dial-up
speed equials 95% of bps of modem.
But some transport protocol (like PPP) can compress data, and modern modems compress too, so, if you have 64K your can download from 7 up 10 k/s. It''s realy speed of this line.

About cable connection - no diference as dial-up (exepct devices which connected to cable, from COM port to to ATM - port, or better. Speed like modems.

About local network.
Ethernet based on collision domains, it mean randomly periods send packets on network and all station read. If netowrk has more station and overloaded speed realy downed . Local network can work good if 2 stations (hosts) high-usage network.
Count hosts in netowrk callucation by formula likes N = (Lan speed) * / ( (Avarage hots speed) + C * (Lan Speed))
Where C equals 0.02 .. 0.06

Ok,

So multicasting will only work on LANs and otherwise for the internet I should be sending packets to each client specifically.

I don''t quite understand the last post though, sorry.

And when you all say "k/s" or "kbs"
are you saying "KiliBYTES per second"
or are you saying "KiliBITS per second"?

My k/s are all kiloBYTES/second
if i use kilobits, i''ll usually say Kbits...(same with Mbits)

My k/s are all kiloBYTES/second
if i use kilobits, i''ll usually say Kbits...(same with Mbits)