Jumbo Frames

[UCrypto]

Dear all,

I would like to know Jumbo frame.I know Jumbo frame is use for connection sensitive application or the applications need massive data input and output.it MTU is more 1500 and less 9000 .I know that.

I want to know benifit of using jumbo frame.

if i want to use Jumbo frame support from telco for our VPN network what kind of device do i need to setup .i mean every devices(router,switch,computers) of our end need to support jumbo frame?

[paul driver · Accepted solution]

Hello

Increasing the mtu size can have provide positive performance increase in your network, However if you have a router/switch/end host that cannot support this larger mtu size you specify then the data will indeed eventually get fragmented, in some cases possibly dropped and drastically increase the cpu/memory process of your router/switch/host.

So I would say you need to understand your own network to have jumbo frames provide a positive result instead of a negative one and In your case I don't think enabling Jumbo frames would have any beneficial increase in performance for vpn users

[Joseph W. Doherty · Accepted solution]

"I want to know benifit of using jumbo frame."

The principle benefit of using jumbo frames, more of the wire's bandwidth is used for transferring your actual data, rather than network overhead (frame and packet header information). (BTW, this can be even more of a benefit for VPN which often adds additional packet overhead). A secondary benefit, many devices performance is tied to how many packets per second (PPS) they can process. Jumbo packets use less packets to transfer the same amount of data, so often a device's effective capacity increases when using jumbo packets.

"if i want to use Jumbo frame support from telco for our VPN network what kind of device do i need to setup .i mean every devices(router,switch,computers) of our end need to support jumbo frame?"

All the devices, end-to-end, need to support jumbo to leverage it. (If you're performing VPN, across the Internet, you're likely to find you cannot guarantee this.)

BTW, some downsides of using jumbo, there's no standard MTU for them. For example, you note jumbos are less than 9K, well usually, but again, there's no standard. Getting MTU wrong can lead to fragmentation, although if PMTUD is working correctly, and being used, jumbo fragmentation might be avoided, but even when working correctly there's a timing impact to on-the-fly MTU reset (which shouldn't be an issue for most applications that would benefit from jumbo).