Tekforums
Chat => Entertainment & Technology => Topic started by: Sara on April 02, 2006, 20:00:06 PM
-
Could you have several wired networks (with, for example, IP vid cameras or other PCs on them) - with each network being connected to its own network card on a single monster PC?
So the PC can be dealing with 3 or 4 networks at once, passing information between them, etc? Would it then be able to communicate at n*network speed (i.e gigabit or 100base-t), where n is number of cards?
-
yep
mostly used where you have a network with a lot of PCs in it, (and big network switches) where the server would be connected to each switch (as well as the switches to each other) to speed things up a bit....
tho that might be a bit out of date now, I guess gigabyte newtorking eliminates most of the need for things like that :dunno:
-
Yeah you could, but these dyas you wouldnt bother. You would either buy a decent high end switch to do things (Ive PoE IP cameras used a few times). The Other alternative if you want to divide Datacomms from IP and Telephony is to use a collection of vLANs to divide the services up, while using one set of infrastructure.
Though on the mius side ive seen vLAN configs used stupidly because The Beancounters thought it would be better than using a dedicated Phone Network (call Center i was escorted round when at uni).
edit: and no, you couldnt gain extra throughput because 1Gb switches are the practical limit on UTP at the moment, anything higher and you really need to get some GBICs. Though you wouldnt spec out large backbone without using Optical these days.
-
Could you have several wired networks (with, for example, IP vid cameras or other PCs on them) - with each network being connected to its own network card on a single monster PC?
So the PC can be dealing with 3 or 4 networks at once, passing information between them, etc? Would it then be able to communicate at n*network speed (i.e gigabit or 100base-t), where n is number of cards?
Theoretically yes, and many computer systems do this, but there is always some inefficiency in a sharing system so you end up with less than optimal throughput.
You could also do the same with Wi-Fi, useing several base transmitters set to different channels. It would still be limited, no more than 3 wireless networks in an area.
-
Could you have several wired networks (with, for example, IP vid cameras or other PCs on them) - with each network being connected to its own network card on a single monster PC?
So the PC can be dealing with 3 or 4 networks at once, passing information between them, etc? Would it then be able to communicate at n*network speed (i.e gigabit or 100base-t), where n is number of cards?
Theoretically yes, and many computer systems do this, but there is always some inefficiency in a sharing system so you end up with less than optimal throughput.
You could also do the same with Wi-Fi, useing several base transmitters set to different channels. It would still be limited, no more than 3 wireless networks in an area.
Serious, do you know this? or are you just googling it?! because some of this bollocks is really getting on my nerves now, if you dont know something for sure say so... that way someone doing a report or similar for uni doesnt lose marks because your ego is too big for your boots.
The only time efficiency would fall to a noticable degree is if your server is under full load, and was inadequate for the task. Much like running multiple PCI cards on a machine (in fact its exactly the same) providing your computer is able to deal with the traffic on the bus then youll have no issues.
Multihomed servers as beaker says used to be common place, less so now again for the reasons beaker mentioned. (notice that most switches have "throughput" figures in their datasheets, telling you how much data it can deal with at the same time... at least thats my understanding of it).
Your question is a bit odd though, seems to suggest your trying to get n*networkspeed performance to a single pc... if by that you mean splitting the data up over multiple cards effectively having parallel transmission going on, Ive no idea if thats possible. Well over my head.
Wireless cells are common, take san francisco for example, and they do not need to be limited to 3. Use of network planning such as directional antennas, placing of units at extreme ranges from each other are just 2 tools I can think of that eliminate the "3" nonsense. Were currently studying this in uni, and I should have some notes on it, if you give us a tick Ill send ye a copy or something. One point that needs to be solved with wireless cells, the major problem... is roaming. Roaming with wifi can be troublesome with different network security at each spot. It isnt seamless like GSM.
Oh and one more thing, now your on wired technologies you have a lot more options open. Optical being the big hitter. Multiple gigabit network technology, I think the highest throughput so far is the stuff they are planning to use at CERN for the LHC (im sure bigsoy has something to do with that.. either him or deathshead, or fc9k.. heck one of those 3), I think the fastest commercial card you can buy (for hellish money mind you) is 8.something GB/s
-
Better to google for an answer anyway than give one your not sure of based on things we are learning :roll:
Sara i would use a switch. Surely it would make sense having dedicated hardware doing the job rather than relying on a Server or PC which are more prone to falling over?
-
Better to google for an answer anyway than give one your not sure of based on things we are learning :roll:
Sara i would use a switch. Surely it would make sense having dedicated hardware doing the job rather than relying on a Server or PC which are more prone to falling over?
not really considering at least I have some grounding in it from tuition, and notes to back it up. Serious appears to googling for anything he can find.
How did the others on this forum find out about things without being first taught? and then expanding upon this by experience? hmm...
Id trust the words from my university lecturers mouth more than I would random googling. :roll:
Also notice the phrase I use. "we are currently studying this" which implies that I am improving upon my prior knowledge on something, not learning which would be from scratch. K?
-
It has absolutely no measurable bearing on performance.
In my checkpoint NG high availability cluster each node has 25 network interfaces on to which 25 seperate VLANs are terminated. All nodes work perfectly and are old Compaq Proliant servers with a P3-866 and 512 MB of RAM. My policy has 188 rules and there are a large number of VPN users, and the cluster barely breaks a sweat.
-
You could also do the same with Wi-Fi, useing several base transmitters set to different channels. It would still be limited, no more than 3 wireless networks in an area.
Er.. arent there about 12 channels you can do? Ive seen 9 or 10 wireless networks running quite happily side-by-side..
-
You could also do the same with Wi-Fi, useing several base transmitters set to different channels. It would still be limited, no more than 3 wireless networks in an area.
Er.. arent there about 12 channels you can do? Ive seen 9 or 10 wireless networks running quite happily side-by-side..
13 in the UK
-
On the Wi-Fi side, (802.11b aps as well, not delt with 11g etc)
all the documentation ive read that came with the access points we have is to make sure you have at least 2 channels of seperation between APs where theyre likely to overlap each others range, mainly so you dont get overlapping interference from the other channels.
so it knocks it down from 13 channels to .... 1,4,7,10,13 - or 5 different usable channels at the very most.
for some reason they seem to default at channel 11, probably US defaults :?
on the lan side, not a lot wrong with a multi-honed server :)
-
Could you have several wired networks (with, for example, IP vid cameras or other PCs on them) - with each network being connected to its own network card on a single monster PC?
So the PC can be dealing with 3 or 4 networks at once, passing information between them, etc? Would it then be able to communicate at n*network speed (i.e gigabit or 100base-t), where n is number of cards?
Theoretically yes, and many computer systems do this, but there is always some inefficiency in a sharing system so you end up with less than optimal throughput.
You could also do the same with Wi-Fi, useing several base transmitters set to different channels. It would still be limited, no more than 3 wireless networks in an area.
Serious, do you know this? or are you just googling it?! because some of this bollocks is really getting on my nerves now, if you dont know something for sure say so...
Yes I goddamn know it. Thing is I may not be answering the same question as you think. You very rarely get 100% of theoretical throughput from such systems, theres probably going to be a bottleneck somewhere.
The second bit has nothing to do with her question here but with the one in the other thread. Actually I should have stopped after the yes as it would have been much simpler answer.
Oh and you can use multiple networks to transmit data between a pair of computers, its been done, but TBH I dont know of any instances where you would need more than 1Gbit/s of data transmitted between a pair of computers uness you have a supercomputing network.
You could also do the same with Wi-Fi, useing several base transmitters set to different channels. It would still be limited, no more than 3 wireless networks in an area.
Er.. arent there about 12 channels you can do? Ive seen 9 or 10 wireless networks running quite happily side-by-side..
Yes but as madmax points out there are some issues with using all of them, I was being uber cautious, you could probably easily get 5 or but that depends on the local bands being unused. If there is another Wi-Fi system in the area you will probably loose 2
-
On the Wi-Fi side, (802.11b aps as well, not delt with 11g etc)
all the documentation ive read that came with the access points we have is to make sure you have at least 2 channels of seperation between APs where theyre likely to overlap each others range, mainly so you dont get overlapping interference from the other channels.
so it knocks it down from 13 channels to .... 1,4,7,10,13 - or 5 different usable channels at the very most.
for some reason they seem to default at channel 11, probably US defaults :?
on the lan side, not a lot wrong with a multi-honed server :)
This tends to happen only one low end consumer kit, with higher end APs interference is not much of a problem. Speaking to Grey on IRC he has 11 aps covering his building. If the max was 3 this wouldnt be possible. San francisco is fully wifid up. Again if the max was 3 then this wouldnt be possible.
Serious your answering from your experiences with crap kit.
Throughput will not be affected by number of cards in a server unless your server is inadequate for the task (as BX mentions above it just doesnt happen).
If you needed multiple gigabits of transfer youd use fiber. You wouldnt use UTP.
-
Could you have several wired networks (with, for example, IP vid cameras or other PCs on them) - with each network being connected to its own network card on a single monster PC?
So the PC can be dealing with 3 or 4 networks at once, passing information between them, etc? Would it then be able to communicate at n*network speed (i.e gigabit or 100base-t), where n is number of cards?
Theoretically yes, and many computer systems do this, but there is always some inefficiency in a sharing system so you end up with less than optimal throughput.
You could also do the same with Wi-Fi, useing several base transmitters set to different channels. It would still be limited, no more than 3 wireless networks in an area.
Serious, do you know this? or are you just googling it?! because some of this bollocks is really getting on my nerves now, if you dont know something for sure say so...
Yes I goddamn know it. Thing is I may not be answering the same question as you think. You very rarely get 100% of theoretical throughput from such systems, theres probably going to be a bottleneck somewhere.
The second bit has nothing to do with her question here but with the one in the other thread. Actually I should have stopped after the yes as it would have been much simpler answer.
Oh and you can use multiple networks to transmit data between a pair of computers, its been done, but TBH I dont know of any instances where you would need more than 1Gbit/s of data transmitted between a pair of computers uness you have a supercomputing network.
You could also do the same with Wi-Fi, useing several base transmitters set to different channels. It would still be limited, no more than 3 wireless networks in an area.
Er.. arent there about 12 channels you can do? Ive seen 9 or 10 wireless networks running quite happily side-by-side..
Yes but as madmax points out there are some issues with using all of them, I was being uber cautious, you could probably easily get 5 or but that depends on the local bands being unused. If there is another Wi-Fi system in the area you will probably loose 2
Multiple physical paths between two nodes will lead to a spanning tree loop - this is a situation that is to be avoided - this brings networks down.
-
On the Wi-Fi side, (802.11b aps as well, not delt with 11g etc)
all the documentation ive read that came with the access points we have is to make sure you have at least 2 channels of seperation between APs where theyre likely to overlap each others range, mainly so you dont get overlapping interference from the other channels.
so it knocks it down from 13 channels to .... 1,4,7,10,13 - or 5 different usable channels at the very most.
for some reason they seem to default at channel 11, probably US defaults :?
on the lan side, not a lot wrong with a multi-honed server :)
This tends to happen only one low end consumer kit, with higher end APs interference is not much of a problem. Speaking to Grey on IRC he has 11 aps covering his building. If the max was 3 this wouldnt be possible. San francisco is fully wifid up. Again if the max was 3 then this wouldnt be possible.
Serious your answering from your experiences with crap kit.
Throughput will not be affected by number of cards in a server unless your server is inadequate for the task (as BX mentions above it just doesnt happen).
If you needed multiple gigabits of transfer youd use fiber. You wouldnt use UTP.
M3ta, you can have as many APs as you like, long as they dont overlap each others transmission area.
simplested explanation i can think of is a chessboard, the black squares being one channel and white the other, long as the next AP is on a different channel, they co-exist nicely.
if you plonk two APs on the same channel, the strongest one will win out.
theres a set of offices below me that look to have installed an AP on the default 11 conflicting with mine above and its caused laptops not to be able to connect to my network.
ive had to bump the AP down a few channels and its resolved it.
theyve also left it unsecured downstairs but more fool them :roll:
in respose to the original question, its gonna be another device in the way but itll behave just like you where using a router with multiple interfaces (wan, dmz, lan).
the PC can send at n*network speed, but the devices communicating across it will still be limited to the slowest link between them,
ive no idea at what point itd saturate the PCI bus on the computer mind (or if it would).
Id more importantly would be asking if its a pc used as a server or just a day to day pc.
servers sit there and dont often have users "working" on them so to speak (firing up word etc), and the OSs normally specify themselves higher priority to background tasks (such as networking services and database requests) rather than a user drawing in paint.
there are multiple interface lan cards for servers, just for reference and ive got my servers on, cant remember the exact name, an ether-channel link to the main switch, using two 100mb links and load balancing across them.
this is very dependant on the switch and the lan card drivers used though, they both need to be aware that they need to do the above otherwise itll SNAFU.
-
Serious your answering from your experiences with crap kit.
Read other peoples crap kit. Actually there have been quite a few grumbles about it in professional computer magazines as well as my own experience in an area where several Wi-Fi networks tried to co-reside.
Multiple physical paths between two nodes will lead to a spanning tree loop - this is a situation that is to be avoided - this brings networks down.
The internet? I know you have to be bloody careful when writing software, which is no longer my area unfortunately, but it has been done.
-
Software has nothing to do with it. Sounds like your confusing deadlocking with this (deadlocking = threads trying to access the same resources at the same time)
What BX is talking about is routing tables.
If you have a spanning tree loop you will end up with each router constantly flooding the network with packets saying "im the right router" and end up with a constantly updating route table. No packets will ever get delivered and youll have a crap load of arp packets flying around.
If you want to learn some decent network topology gubbins I would be quite happy to pm you a link to a lecturers notes however they wont make much sense without the talk that accompanies them.
Madmax: Youve said what im saying :) the max is not 3. :D lol.
-
....
Multiple physical paths between two nodes will lead to a spanning tree loop - this is a situation that is to be avoided - this brings networks down.
The internet? I know you have to be bloody careful when writing software, which is no longer my area unfortunately, but it has been done.
simplest example of spanning tree loop is getting two or three switches and wire them up so they form a loop.... A to B, B to C, C to A.
et. voila, instant chaos until one of the switches realises that its got a loop on two ports and switches one or both of them off... if it realises that is....
-
9/10 the port just flaps - and rather annoyingly it flaps with a vlan interface