IRC bandwidth question

Plasma · Newbie Joined: 10 Dec 2003 Posts: 63

Hey,

I have a small question concerning bandwidth usage for an IRC server and a possible amount of users.

Currently this IRC server is running UltimateIRCd 2.8.7 with 150-200 concurrent users, and is functioning fine - The largest channel hovering around 60-80 users at one time.

I was wondering if there was a reliable means (could someone estimate from experience?) for how much bandwidth would be required for approximatly 1000 concurrent clients, all possibly in the one channel.

At the moment I believe the connection is running on a 2Mbit link (both up and down).

How much bandwidth would be required without lagging/causing clients to disconnect? The machine would be able to handle the connections fine however.

The discussion in the channel would most likely be ~1-2 sentences/second from about 3 people if thats any indication.

Any help would be appreciated.

Thankyou

Pierce · none Joined: 09 Feb 2004 Posts: 47

its a good question, my sysadmin just said to me today, that 1000users = 1mb/s or 300GB transfer/month, which not many if any ircd providers give. then you have complexity of linked server, and services,

to try and bring down that usage use the "zip" links feature on unrealircd if your not already doing it. also where you have linked the servers can also increase transfer, try and map all your servers, and link them togethere in small pockets.

Pierce

U · Eleet Joined: 18 Jun 2003 Posts: 521 Location: IRC

If you're using a single server, the figures you're giving could be accurate, but most networks won't use a single server.

It also depends on what exactly your users are doing. 1000 clients that chat actively for say, 1 hour per day and idle the rest of the time won't use as much as clients that chat actively for 4 hours per day and disconnect.

Also, though you will see a good amount of traffic from server to server interaction, you will see alot more servicing individual users.

My main IRCd running Unreal3.2 (with ziplinks) uses roughly 30GB a month. The usercount fluctuates from 1000-1250 users any given day. The reason why I call this the "main" ircd is because it also has services and neostats (with OPSB/Secureserv) on it. I figure it uses the most bandwidth of any hub because it has to send not only data to servers and users locally, but it also has to send services and neostats data to the entire network. It averages about 75 local users also. The network has 18 client servers however that distribute the load-so I'm probably using less (per server) than you would if you had 1000 users and only 10 servers. Clients take up alot of the bandwidth consumption-and with my users spread over 18 servers, the client-server interaction is reduced. My average leaf uses around 12GB a month currently.

It really helped going from Unreal3.1.x (no ziplinks) to 3.2. This reduced the bandwidth consumption roughly 30% per server.

If you're looking to expand or maybe change providers to accomodate your growing network, I would suggest looking at the bandwidth provided closely and try to find a provider with "tiered" rates-and preferably with some kind of monitoring you can access so you can keep an eye on your consumption. There will be a lot of factors involved in how much you actually use-and with a tiered provider, if you see you're getting closer and closer to your monthly limit, you can change to a higher package before going over your limits. Most providers will charge a lot more for overage than for a higher package. If you're getting overly large too, it may be cheaper to go with another server on a seperate provider (for redundancy) and to spread the load, instead of taking one server and upping it even further. You'll have to look at the cost of each and make a decision-sometimes creating another access point via another shell account is cheaper than moving one up. (You could get another shell on the same provider, yes, but thats not always best, especially if that shell would be on the same box as the first one, that box goes down for maintance and you're down TWO servers now instead of one). I did this in one instance-it would have cost me $25 to double the bandwidth on one of my servers, but I found another provider that would give me another server with the same bandwidth as the first one for $20 a month, and by having 2 servers I reduced the load on the first server down enough that I'm now safely only using 70% of the bandwidth provided on the first provider again. I usually look at upping capacity or reccomend it occur to people linked to me when they start consuming 85% of the alloted bandwidth allowed per month.

I was lucky in the fact that I had staff that also wanted to enter the server realm, so when I needed more capacity also, I got people who stepped up and added servers. This helps.

You will definetely have to keep an eye on it. I check my bandwidth figures frequently and you should encourage people linked to you to do the same. You'll find servers will depart quickly if they go over and suddenly a $20 shell became a $35 because of overage without any warning. It may be something to discuss with them when they link too-make sure they understand the sustained costs, and things they need to keep an eye on, and the fact that if you DO grow, you may need a larger monthly commitment from them in the future to keep the server going.

Good luck experimenting with it-and try to avoid overage!

Jason · Posted: Feb 18, 2004 10:10am Post subject:

I ran the largest IRC servers on Undernet (at the time) for about 4-5 years.

I can't tell you what your bandwidth usage will be due to the fact that more users in the same channel will eat up more bandwidth, and more users on a network will also use varying amounts of bandwidth...

But I can tell you that:

1) ~2/3rds of your bandwidth will be outgoing to your local users

2) I was able to handle 9,500 concurrent users on Undernet only using two dedicated T1s.

Keep in mind my server was for AT&T, and we were on a major backbone there, which did all our network filtering. So DoS attacks didn't eat up any of the bandwidth, otherwise two T1's would not have survived for long.

Horizon · Posted: Feb 18, 2004 4:28pm Post subject:

Small network stats but here you have it.

Network Statistics For AccessIRC

www.elric.net/ircgraph

MRTG bandwidth use stats for a single client server

http://www.sask.cc/mrtg/eth0.html

Hope this helps give you an idea Wink

Plasma · Newbie Joined: 10 Dec 2003 Posts: 63

Thankyou for your replies they have been very helpful.

The reason I ask this is that the network im on is only a small network (one server, as I said 150-200 users) and if there were to be an influx of users for a few hours (specifically for an interview with developers for a game) - just wanting to know if the server (and bandwidth, we have a 2Mbit link up/down - GB/month transfer is not important) is able to handle the connections...

So you would probebly see (just using over realistic figures here) 1000 users watching 4 users chatting on an average of 1-2 sentences/sec (if not less), all in the same channel...

Any further info for the above would be great as well, thanks!

Ben_ · none Joined: 09 Mar 2006 Posts: 2

1000 * 20 * 4 / 1.5 = 53333.33 bytes = 52.08 kilobytes = 0.40mbit

1000 users, each sent about 20 bytes from 4 people who send a message each once in 1.5 seconds(between 1 to 2 seconds)

Just make sure that all the other people can't talk cause it can get really nasty if about 30 of them start talking..

That'd be like..
1000 * 20 * 30 / 1.5 = 400000 bytes = 390.625 kilobytes = 3.05mbit
Which your connection can't handle.

Hope this helps
- Ben

EDIT: Wah crap lol, I just found that post on google and was like I have to answer.. This is like 2 years ago! My bad Razz

Sorry

box · none Joined: 27 Jan 2006 Posts: 15

As long as your on a "chat only" network bandwidth is usually no issue, However networks with dccs that run 24/7 will therefore eat and eat and eat bandwidth, so if you have these on your network this could be a potential of alot of bandwidth usage, also included in this is dead bottler clients that continue to scan daily.

Ofloo · none Joined: 16 Jan 2004 Posts: 24

irc doesn't use that much bandwidth when i had 3000 users where most of the users where in one channel (channels of 800 users) it used constant 60kb/s on one server ! which is a 0.5mbit or 600 gig/m if i may beleve the calculations of dedicated server providers that 1200gig is about 1mbit !

now.. it all depends if the users arn't all in one channel and more spread out then it uses less bandwidth the more big channels the more bandwidth

imagine every quit every msg send to every user on your network at once if all your users are in one channel that is a lot of bandwidth. also some ircd's use more bandwidth then others, i noticed that hybrid could beter handle this then unrealircd at that time .. one of the biggest reasons why i changed from unreal to hybrid

also the reason why i banned xdcc because they create a lot of traffic that is useless and it attrackts a lot of dummy clients. that don't talk at all.

Ella2006 · none Joined: 24 Mar 2006 Posts: 1

Hi pple!
i'm new here and i have a big big question...how can i find out the servers of the internet cafes of the pples to who i talk?
i'm sure that some of u know this...it's of capital importance to me so pls help me with this! Neutral

katsklaw · Posted: Mar 24, 2006 4:28pm Post subject: Re: Bandwidth

m00c0w · none Joined: 07 Dec 2005 Posts: 28

katsklaw · Posted: Mar 25, 2006 9:19am Post subject: