Collisions Galore!

[SteveC]

OK guys, I do know a bit about networking, but I am getting the little collision light on my hub almost permanently on and I don't know why!

I have a 10/100 8 port no-name hub and the network works 100% perfectly. I am playing a DVD across it now, and am also copying 100's of MBs of data across to another PC and no probs (the DVD playback is still perfect). (The utilisation LEDs go off the scale though!)

But when any constant data is being transferred, like this DVD playing, the 100mbps collision LED is flickering like mad!

Any ideas? or should I ignore it?

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Cheers,
Steve

"Life is what we make of it, yet most of us just fake"

[Snake-Eyes]

I'd say ignore it, but then I'm not networking expert myself, so this is all from what I've read online (much of it in here). If I understood it right, both NICs (assuming 2, more would be the same, just more often), are constantly broadcasting info to the network while active. There's bound to be collisions between those packets, at least with a standard hub setup. Others have advocated switches instead of hubs, to both address this problem, and also to gain full use of the bandwidth. In fact, I'm thinking of getting a cheap 4 port switch to replace my hub, too (only have 2 PCs and a cable modem), just so I can relieve all doubts about why my ping spikes in UT when both my wife and I are online.

Oh, and the collisions ARE normal with hubs, of that I'm sure. With only 2 PCs and a cable modem, running 2 10/100 cards (the modem's 10mbps max), and a 10/100 autosensing hub, I get that a lot when tranfering files between the two systems. It's not really that big an issue either, at least with this small a setup.

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Ace



[This message has been edited by Ace (edited 18 July 2000).]

[SteveC]

I may have to invest in a switch too - 8 player network games begin to stretch a 10/100 hub when some are 10mb some are 100mb and 3 of them are copying Half Life off the other!

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Cheers,
Steve

"Life is what we make of it, yet most of us just fake"

[thecurse]

choice 1) ignore it (which is ok for a small home network)

choice 2) time for switches instead of a hub

choice 3) run a network utilization program to see how bad it really is. i recomend sniffer pro 2.5

if you need the extended eval version of sniffer pro just give a shout and i can hook you up soon as i get home from work.

ps i am a sys admin for a livign so i know a little about networks

[Snake-Eyes]

Hehe. Sounds like fun though, Steve. Now I just wish there were more MURCers in my area, since I can't make it to the places that the LAN parties are usually held yet.

Thanks for the extra info there, thecurse.

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Ace

[dZeus]

maybe you should change the connection to half-duplex on all the connected NICs?

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- What do you get when you put N nVidia whores in a circle and each one pats the person on their right on the back and says "nVidia wins 3dfx and Michael Knight any day of the week!" ?

- You get N people with a boosted ego, and no-one loses anything; keep up the good work, boys!

[thecurse]

dZeus : half duplex mode would not cause that many less collessions.

stevec: another thing to do is get rid of unneeded protocols like netbeui

[SteveC]

I only use TCP/IP.
Other networks I've set-up/used have hardly any collisions - especially when only two PCs are talking to each other! Could it be that my hub is misreporting collisions?

Anyway it works...for now!

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Cheers,
Steve

"Life is what we make of it, yet most of us just fake"

[Taz]

Of course you could always switch to Token Ring that would put an end to the collisions, only joking

[SteveC]

Don't Taz! I use a T/R network at work - I even have an 8 port 16mbps MAU which I *could* use (but I won't!).

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Cheers,
Steve

"Life is what we make of it, yet most of us just fake"

[Greebe]

I use TCP/IP and NetBUEI. NetBUEI is the best/simplest way to share files and printer(s) on a peer to peer network without neglecting security! My home network consists of three systems using generic 10/100 nics and a 5 port autosense stackable NDC fast ethernet hub. Nat32 for internet sharing on a single V.90 dialup and BID for my firewall. I get the occasional collisions but that has never caused a problem for me at all.

[Helevitia]

Steve,

Collisions are a normal part of any shared network such as yours. what is happening is that all of your PC's are set to either 10/half or 100/half. With half duplex, it is normal to see collisions. In fact, you are on what is called a collision and broadcast domain which means everyone shares the same stuff, good or bad.
Collisions happen when two hosts listen on the wire for traffic, hear nothing, then send data at the exact same time. The two packets collide which both hosts hear. At this point, both hosts implement what is called a back off algorithym which means they stop sending data for a random amount of time(msec). Then one of them sends there packet again which will unlikely be at the same time as the other host which he had problems with the first time. This is called CSMA/CD(Carrier Sense Multiple Access w/ Collision Detection).
Now, you are streaming Audio, Video, and Data all at the same time across a hub which is getting over subscribed and therefore lots of collisions occur. blah blah blah, sorry for the long post. I think you get the idea.

Dave

[Jeff]

If you only have 2 PC's connected you should use a cross over cable between them and eliminate the hub. You can only connect to a hub a 1/2 duplex and the crossover would make your connect full duplex, 100 both ways. Should work better.

JP

[MultimediaMan]

You might want to check oiut this little article at Microsoft:
http://support.microsoft.com/support...-US&SD=gn&FR=0

There is a downloadable patch that addresses what may be your problem.

I have a five computer network myself here at home: Collisions are common during heavy traffic, but surfing the internet and trnsferring files between two computers generate many fewer collisions after this patch is implemented.




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My (Current) Primary system:

Abit BE6 (PL BIOS)
P3 450
384MB PC-100 SDRAM (Non-ECC)
Matrox Marvel G200-TV AGP (NTSC) 16Mb w/ HW-DVD Module v2.6 BIOS
Quantum 3D Obsidian X-24 Voodoo2 card
3Com 905B-TX NIC
SBlive (W/ OD I/O Card, Liveware 3.0 + Update)
ADS Cadet Radio Data AM/FM Card (8 Bit ISA)
3x WD AC28400 EIDE HDDs (ATA66 Enabled)
Creative DVD5241E EIDE 5x DVD-ROM
M/S Windows 98SE (English)
DirectX 7a

My (Current) Secondary system

Data General/ ALR 2650 Mobo (v6.004 BIOS)
2x P2 266 (SMP)
128 MB PC-100 SDRAM (ECC)
2 x Creative Savage 4 32MB PCI Adapters
3COM 905B Onboard Adaptec AIC7895
Onboard Intel 82558 NIC
Onboard Cirrus Logic SVGA adapter (Disabled)
Adaptec 2930U SCSI adapter
Creative ModemBlaster 5630 Data/Voice/Fax Modem (PCI)
Creative SBLive! (Full Version)
2x WD 4.5 GB Enterprise SCSI3 HDD
Panasonic LK-MW602 CD-R
Nakamichi MBR 7.4
Windows 98SE/NT Server Dual boot
DirectX 7a/SP-6

Tertiary system:
Dell Inspiron 7100 Laptop

[Snake-Eyes]

Thanks for the info, MultimediaMan. I was just talking with a friend last night (hehe, not you this time, Jorden) that is frustrated because he hasn't been able to locate the Win9x TCP/IP patch (for hsi Win98SE system), and I think this is it. He claims that his system had much better performance with that patch installed, but that he can't locate it again (after several reinstalls), so I'll send this to him and see if this is it. And after I check my TCP/IP retrans stats (the note at the end of that page says to use 'NETSTAT -S' at the command prompt), I may end up using it too.

Thanks again!

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Ace