Gigabit switch with 9 kB Jumbo Frames

[warsur]

I just upgraded the speed of part of the Lad using a gigabit switch to connection my disk station with Lan PCs.
The switch is D-link DGS-1008D with 9kB Jumbo Frames (http://www.d-link.com.hk/main.asp?style=products2&id=22&id2=106).

Do I need to make necessary setting in my Disk Station(System->Lan ->Link Status-?

Any co-relation between kB and MTU?

[Franklin]

Warsur-

To maximize the potential of Gigabit Ethernet, all devices on your network must have the same amount of jumbo frames. So on your Disk Station, you would have to set the MTU to 8000, and your PC must support the MTU value.

To read more about MTU, click here.

[warsur]

I cannot post my capture here.
In my computer:

Control Panel-> system->hardware->Device Manager-> Network adapter->(choose my network)

My driver's jumbo frames setting of the PC have four options:

1. Disable,
2. 4088 bytes
3. 9014 bytes
4. 16128 bytes

and the Gigabit switch also mentioned 9k jumbo frames.

but the synology diskstation mentioned 2000, 3000, 4000, 5000, 6000, 7000,8000 MTU.

How can I match them all together?

[Franklin]

Set your computer for 9014 bytes, and set the Synology Server for 8000. All three products will negotiate with each other and your computer will operate at 8000 MTU.

[warsur]

Thanks for your helpful advice.

[uSharkRider]

Hi!

What happens with the internet connection optimation when you change to 9kB Jumbo Frames? What I mean is, if I have a ADSL internet connection that want smaller packages to be able to function at best and you set the computer and diskstation to handle bigger packages. Can you have all traffic to the ADSL modem to be in smaller packages at the same time as bigger packeges between the computer and diskstation?

Regards,
Ulf Carlsson

[Franklin]

Hi!

What happens with the internet connection optimation when you change to 9kB Jumbo Frames? What I mean is, if I have a ADSL internet connection that want smaller packages to be able to function at best and you set the computer and diskstation to handle bigger packages. Can you have all traffic to the ADSL modem to be in smaller packages at the same time as bigger packeges between the computer and diskstation?

Regards,
Ulf Carlsson

Nothing should happen to your internet connection, since the DSL modem transmits packets at 1500 bytes, the computer will recieve the information at 1500 bytes. By setting the MTU to say 9048 bytes on the computer, all you really did is increase the limit at what the computer and transmit and recieve information at. It will still recieve packets from the modem at 1500 bytes and Disk Station information at 8000 bytes

Hope this answers your question

[uSharkRider]

Hi!

That was good news ideed! I will change my MTUs as soon as possibe!

Regards,
Ulf

[beonist]

What does "all devices on your network must have the same amount of jumbo frames" mean?

I am considering a 10/100/1000 switch (Linksys EG005W) that I would uplink to a Wireless G broadband router w/ 4-port 10/100 switch (Linksys WRT54G).

I understand that connecting my gigabit enabled computer and the CS406e to the gigabit switch will work with MTU set at 8000. I understand from the conversation with uSharkRider that both those units can receive packets smaller than the MPU setting. My question is whether non-gigabit devices can "receive" data from a CS-406e with the MTU set to 8000.

If the CS-406e is set to MTU 8000 will:

1. a 10/100 device connected to the gigabit switch be able to receive good data?

2. a device connected to a wired port on the 10/100 router be able to receive good data?

3. a device wirelessly connected to the router be able to receive good data?

[Franklin]

When setting the MTU to 8000, it means is sets the maximum size of packet that a device can transmit/receive.


So, if the PC 1 is at 1500, PC 2 is at 8000, and CS-406 is at 8000, and the router is at 9000, then PC 2 and CS will have 8000 MTU, while between PC 1 and CS will be 1500 MTU

So, to answer all three of your questions, yes all scenarios will still receive good data.

[beonist]

Thank you for the prompt reply Franklin.

Two more questions please:

1. Do you think I will actually notice a difference using gigabit lan with the CS? The files I am moving back and forth are in the 4Gb range.

2. Right now I have about 300Gb to upload. Will the upload be faster over the lan or from a usb drive attached directly to the CS?


BTW: I did see the FAQ that showed ~10% upload/~25% download improvement for the DS-106e using gigabit lan. Unfortunately I don't know how the DS's hardware compares to the CS's hardware. [Ref: http://www.synology.com/enu/support/hel ... p?q_id=242 ].

[Menno_2]

Hi Franklin,

I use a Gig NIC card, and enabled the jumbo frames, but also my internetconnection MTU is set on 1500, so this is not true, because the MTU is written either on 1500 or on 9000 you cannot get both working.
Once you enabled your Gig NIC card at 9000 jumbo frames the MTU value of your TCP/IP settings will also be set on 9000 so how is it possible to combine incoming internettraffic at mtu 1500 on a NIC card which has been hardware config programmed on jumbo frames 9000?

Or do i need to use 2 NIC cards one for my incoming internet
and one for the videostreaming?

Thx



Nothing should happen to your internet connection, since the DSL modem transmits packets at 1500 bytes, the computer will recieve the information at 1500 bytes. By setting the MTU to say 9048 bytes on the computer, all you really did is increase the limit at what the computer and transmit and recieve information at. It will still recieve packets from the modem at 1500 bytes and Disk Station information at 8000 bytes

Hope this answers your question[/quote]

[Franklin]

Menno_2

Please do not cross post; your question was answered via PM