[Sleepy8686]

Hi guys,


I just installed the "top" half of my gigabit network meaning I have a bedroom upstairs that has our two main desktops,two Xbox's, printer etc as well as the modem being located in this room.


The way things are hooked up as of now:


D-Link Router is running both Xbox's and printer also a Cat6 line into a 10/100/1000 switch which is connecting the two desktops. I played around last night doing some transfers between the 2 pc's as well as some streaming and was getting about an average of 60 Mbp/s transfer rate which from what I've read is about 480 Mbits/s is this correct? Also, from what I've been reading 300 Mbits/s is considered to be the high end is this also correct?


My second question revolves around installing the "bottom" half of the network. This is going to consist of a Windows Home Server and Western Digital WD Tv Live into a finished basement.


My plan is to run a Cat6 from an open port in the gigabit switch upstairs down to the basement which would then go into another of the same gigabit switches and run to the WD TV and server. I know the WD TV is not gigabit capable but seems like the logical solution to keep a gigabit connection to the server.


Is there any foreseeable flaws in this set up or another suggestion on how to do it? I've already purchased everything so unless there is a significantly better way to do this I'd rather just stick with what I have.


Thanks for reading!

 

[huntrm]

I see no flaws with the approach. Simple enough, capable of supporting expansion where you place your switches. The switches are 'dumb where they don't assign IP addresses, as your router will do this.


I've run cable from one Dlink switch to another switch, and then to ANOTHER switch. No issues. Gigabit is way to go.

 

[Sleepy8686]



Quote:
Originally Posted by huntrm /forum/post/18110179


I see no flaws with the approach. Simple enough, capable of supporting expansion where you place your switches. The switches are 'dumb where they don't assign IP addresses, as your router will do this.


I've run cable from one Dlink switch to another switch, and then to ANOTHER switch. No issues. Gigabit is way to go.

Good to hear, thanks for your reply

 

[MrBobb]



Quote:
Originally Posted by Sleepy8686 /forum/post/18109760


Just installed first half of my Gigabit network

Well no wonder you are only getting HALF of the theoretical max bandwidth.

Assuming nothing wrong with your cabling and u are testing the right way, you should get more than 480 mbits/s. Maybe the el-cheapo switch can't handle it? OTOH, u haven't mention any mission critical, high bandwidth application, so maybe 480 mbit/s is good enough for u currently.


Of course u should run gigabit into the server. Wouldn't u want your cell provider to have max bandwidth so when more users (and processes) join in, it won't choke? At some point, u may even install another NIC on the server and double the bandwidth to it.

 

[Sleepy8686]



Quote:
Originally Posted by MrBobb /forum/post/18111664


Well no wonder you are only getting HALF of the theoretical max bandwidth.

Assuming nothing wrong with your cabling and u are testing the right way, you should get more than 480 mbits/s. Maybe the el-cheapo switch can't handle it? OTOH, u haven't mention any mission critical, high bandwidth application, so maybe 480 mbit/s is good enough for u currently.


Of course u should run gigabit into the server. Wouldn't u want your cell provider to have max bandwidth so when more users (and processes) join in, it won't choke? At some point, u may even install another NIC on the server and double the bandwidth to it.

I dont think these would be considered "el cheapo" correct me if im wrong

http://www.amazon.com/D-Link-DGS-220...f=pd_rhf_p_t_3


And no I dont have any critical high bandwidth application its going to be for streaming media, blue rays, music etc and backups of course.


Everything I read was saying that if you can get 300Mbits/s then you are doing well but then of course it seems as though there are alot of conflicting views on the actual speed you should be able to attain. Converting to Mbps that would be a max 125Mbps with a 10-11% overhead so I'm thinking I'm not too far and havent tried to "tweak" anything either.

 

[MrBobb]

You are probly talking about a single application max attainable speed with today's technology. if that's the case 480mbit is about it. But assuming no bottlenecks anywhere EXCEPT imposed by the gigabit, shouldn't u get close to 1,000mbit/s? That's why they call it gigabit right. Since u asked a networking question, I assume that's the main piece of your concern. If you are curious, try to find a tester that uses no HD (bottleneck), instead does memory to memory transfer, and that should give u a higher number.

 

[WonHung]

Your transfer speeds look fine to me. Getting fast performance rates on Gig is a combination of many things of which involves I/O performance of both end points. This means bus contention, bus type, hard drive subsystem, memory topology, etc, etc.


As far as the comment about el cheapo switch, even with my more expensive switches, I'm getting around the performance you are getting. My expensive switches include a Netgear GS748TP and a Cisco Catalyst 2960G.


I've been saying this in numerous threads here concerning uplinking of switches. Yes, you can just use a single uplink connection between switches and you will be fine the majority of the time. But if you are after a high performance configuration, a single uplink connection is NOT optimal. It sounds like you are after the best performance you can get from a Gig switch fabric. If you have minimal contention between devices on each switch talking over that SINGLE 1 Gig connection, then you'll probably never have a problem. But if you are doing multiple high performance transfers between a number of devices each located on a different switch, then you WILL see contention. To get around this issue, you either have to get a bigger switch and have ALL devices connected to the same switch (to utilize transfers across the switch's backplane) or you have to use a port channel/etherchannel connection between the two switches. Port channel/etherchannels are logical groupings of more than one physical link between devices. Port channel/etherchannels support up to 8 physical links grouped together. So in theory you will have about 8 Gb of bandwidth capacity if you group 8 1 Gb links. But this does not mean your transfers between switches are at 8 Gb. Each network session will still be over a single Gig connection. But because there are more links available, the switch can either round robin each successive connection to another available link or use more advanced hashing algorithms to pick an appropriate link path. The only problem with trying to use port channel/etherchannels is that only managed switches have this functionality.


One other option will also provide better inter switch peformance but is probably even more out of the question than getting a managed Gig E switch is to find a switch with 10 Gb uplink ports. The cost to get into a 10 Gb capable switch is even more than getting into a managed Gig E switch.

 

[WonHung]

One more performance tweak I forgot to mention. You can try to boost performance by utilizing jumbo frames. Jumbo frames are frame sizes greater than 1500 bytes which is the default size for standard ethernet frames. If you increase the frame sizing, you have to do so with each device you want to participate in jumbo framing. Your switch will also have to be able to support jumbo frames.

 

[sic0048]



Quote:
Originally Posted by Sleepy8686 /forum/post/18109760


Hi guys,

My second question revolves around installing the "bottom" half of the network. This is going to consist of a Windows Home Server and Western Digital WD Tv Live into a finished basement.


My plan is to run a Cat6 from an open port in the gigabit switch upstairs down to the basement which would then go into another of the same gigabit switches and run to the WD TV and server. I know the WD TV is not gigabit capable but seems like the logical solution to keep a gigabit connection to the server.

If you can run 1 cat6 wire, odds are you can run more than 1 at the same time. If this is the case, I would recommend you run at least 2 cat6 wires and forgo the 2nd switch downstairs. Even if you only run two line and end up with more than two devices downstairs, you could always run the server on it's own cat6 wire directly to the main switch, and then run all the other appliances off a 2nd switch downstairs.


But the more switches you add to the mix, the slower the potential speeds will be. This is because you are sharing 1 cat6 wire with all the devices on the 2nd switch. If you wire them separately, then each device has its own cat6 wire and bandwidth.

 

[MurrayW]



Quote:
Originally Posted by WonHung /forum/post/18113889


Your transfer speeds look fine to me. Getting fast performance rates on Gig is a combination of many things of which involves I/O performance of both end points. This means bus contention, bus type, hard drive subsystem, memory topology, etc, etc.


As far as the comment about el cheapo switch, even with my more expensive switches, I'm getting around the performance you are getting. My expensive switches include a Netgear GS748TP and a Cisco Catalyst 2960G.


I've been saying this in numerous threads here concerning uplinking of switches. Yes, you can just use a single uplink connection between switches and you will be fine the majority of the time. But if you are after a high performance configuration, a single uplink connection is NOT optimal. It sounds like you are after the best performance you can get from a Gig switch fabric. If you have minimal contention between devices on each switch talking over that SINGLE 1 Gig connection, then you'll probably never have a problem. But if you are doing multiple high performance transfers between a number of devices each located on a different switch, then you WILL see contention. To get around this issue, you either have to get a bigger switch and have ALL devices connected to the same switch (to utilize transfers across the switch's backplane) or you have to use a port channel/etherchannel connection between the two switches. Port channel/etherchannels are logical groupings of more than one physical link between devices. Port channel/etherchannels support up to 8 physical links grouped together. So in theory you will have about 8 Gb of bandwidth capacity if you group 8 1 Gb links. But this does not mean your transfers between switches are at 8 Gb. Each network session will still be over a single Gig connection. But because there are more links available, the switch can either round robin each successive connection to another available link or use more advanced hashing algorithms to pick an appropriate link path. The only problem with trying to use port channel/etherchannels is that only managed switches have this functionality.


One other option will also provide better inter switch peformance but is probably even more out of the question than getting a managed Gig E switch is to find a switch with 10 Gb uplink ports. The cost to get into a 10 Gb capable switch is even more than getting into a managed Gig E switch.

I have two 16 port 10/100/1000 Netgear switches that currently have 1 Cat5e or 6 (not sure which) cable connecting them. Each switch has 2 or 3 empty ports. Are you saying that I might get better performance by using these empty ports to add more connections between the 2 switches, so that instead of 1 cable connecting the two switches, I would have 3 or 4?

thanks,

Murray

 

[jibjib]

Interesting subject that hits close to home, as I’ve just finished the upstairs half of my gigabit system too. The downside of having two switches (one up and one down stairs) is something I had not considered, but in my case should be OK. I have a server and four computers upstairs, with two LAN printers and will run a line to a switch downstairs to interconnect the home theater and another computer or two to the system. The heavy duty file transfers will stay predominantly on each single floor, but the systems are interconnected for obvious reasons.


As Murray asked, would there be a benefit to having two active lines between the two gigabit switches?


Also, how does one measure system speed?


Jack

First post of a long time lurker

 

[Sleepy8686]



Quote:
Originally Posted by WonHung /forum/post/18113900


One more performance tweak I forgot to mention. You can try to boost performance by utilizing jumbo frames. Jumbo frames are frame sizes greater than 1500 bytes which is the default size for standard ethernet frames. If you increase the frame sizing, you have to do so with each device you want to participate in jumbo framing. Your switch will also have to be able to support jumbo frames.

Thank you for this. I have been so busy drilling holes, running lines and building my new WHS I hadnt had much time to look at possible optimizations but I do remember reading about this before I started buying everything. I looked at some articles about jumbo frames and have played around with my pc's nic and set it to 3KB MTU and am now getting 100Mbps + transfer speeds

I'll try tweaking my server's as well when I get home.

 

[Sleepy8686]



Quote:
Originally Posted by MurrayW /forum/post/18114603


I have two 16 port 10/100/1000 Netgear switches that currently have 1 Cat5e or 6 (not sure which) cable connecting them. Each switch has 2 or 3 empty ports. Are you saying that I might get better performance by using these empty ports to add more connections between the 2 switches, so that instead of 1 cable connecting the two switches, I would have 3 or 4?

thanks,

Murray

I believe what he is saying here (which makes sense) that a single line feeding two switches is fine unless you are running a heavier traffic network doing multiple transfers at the same time. If thats the case then you would be better off running a separate line to each of your switches. I hope that also helps the other poster above me.

 

[David Feller]



Quote:
Originally Posted by MurrayW /forum/post/18114603


I have two 16 port 10/100/1000 Netgear switches that currently have 1 Cat5e or 6 (not sure which) cable connecting them. Each switch has 2 or 3 empty ports. Are you saying that I might get better performance by using these empty ports to add more connections between the 2 switches, so that instead of 1 cable connecting the two switches, I would have 3 or 4?

thanks,

Murray

Most "managed switched" support Link Aggregation (LAG) but most home switches do not. If i supports LAG, you can log into the switch and designate specific ports to be part of the spanning tree. Without the setup, or with unmanaged switches, normally you get a broadcast storm - a loopback situation where all the activity lights will just go ballistic.


David

 

[WonHung]



Quote:
Originally Posted by MurrayW /forum/post/18114603


I have two 16 port 10/100/1000 Netgear switches that currently have 1 Cat5e or 6 (not sure which) cable connecting them. Each switch has 2 or 3 empty ports. Are you saying that I might get better performance by using these empty ports to add more connections between the 2 switches, so that instead of 1 cable connecting the two switches, I would have 3 or 4?

thanks,

Murray

No. The only way you can properly utilize more than one connection between switches is if they are set up as a port channel/etherchannel. To be able to do this you MUST have managed switches on both ends.


If you wire more than one connection between two unmanaged (dumb) switches, you will either have some performance issues with one or the other link flapping due to spanning-tree setting the port to block instead of forward. Some switches will attempt to reset a port which is in a blocked state which will cause the port to flap. Spanning-tree is a protocol which attempts to prevent switch loops. If you wire two switches which do not run spanning tree with more than one link, you'll create a switch loop and you'll quickly bring your network to its knees as frames go round and round till the switch stops forwarding frames.

 

[WonHung]



Quote:
Originally Posted by David Feller /forum/post/18115814


Most "managed switched" support Link Aggregation (LAG) but most home switches do not. If i supports LAG, you can log into the switch and designate specific ports to be part of the spanning tree. Without the setup, or with unmanaged switches, normally you get a broadcast storm - a loopback situation where all the activity lights will just go ballistic.


David

This is correct....without my verbal diahrea in my response to Murray.

 

[David Feller]

It does, however, make a great flashlight as all the lights on the switch come on - kind of the IT equivalent of using your phone to find your keys in the dark

 

[Sleepy8686]



Quote:
Originally Posted by WonHung /forum/post/18113900


One more performance tweak I forgot to mention. You can try to boost performance by utilizing jumbo frames. Jumbo frames are frame sizes greater than 1500 bytes which is the default size for standard ethernet frames. If you increase the frame sizing, you have to do so with each device you want to participate in jumbo framing. Your switch will also have to be able to support jumbo frames.

Another question about this since I'm by no means an expert

I changed the setting for jumbo frames and got the vast improvement as stated. I then logged into my router a bit later as I wanted to turn the wireless security on.


After doing so I decided to go ahead and reboot the router through the web interface and for some reason my transfer speed dropped down to what it was before. It was good but not 100Mbps+. I then changed the jumbo frames from 4KB MTU and back to 3KB MTU and the speed was back again. Is this expected behavior?