Routers: What Are Jumbo Frames and why do I need them?

[Paul Goodwin]

Some routers' specs specifically mention that they handle jumbo frames (with a number like 9K). I have a network with 2 iphones, two ipads, 4 computers, two networked Blu-Ray players, and 3 computers, all of which are operating simultaneously a lot of the time.

Some other companies seem to be using the fact that they support jumbo frames as part of their selling points. How do they help?

I asked Cisco Chat support about the RVS4000 and whether it supported them on both the WAN and the LAN. They said not on the WAN. They also said "

It appears under the L2 Switch tab you can input a Max Frame type.....

I don't see anything that actually says jumbo frames but I believe you can put in a value.....

after the device is setup you can navigate to the L2 Switch option and it has a Max Frame value"

I'm not sure whether this router supports jumbo frames or not. I have a short list of wired gigabit routers that I'm considering for purchase and the RVS4000 is on the list.

I need to learn more about this topic so any help or pointers to stuff to read would be greatly appreciated.

[mpyhala]

Hi Paul,

Thank you for posting. Please take a look at the following pages which should give you a good understanding of Jumbo Frames:

http://en.wikipedia.org/wiki/Jumbo_frame

http://www.smallnetbuilder.com/lanwan/lanwan-features/30201-need-to-know-jumbo-frames-in-small-networks

RVS4000 review:

http://www.smallnetbuilder.com/lanwan/lanwan-reviews/29910-linksys-rvs4000-great-features-but-slow-downloads?start=4

(Note the last sentence of this review)

The RV220W has Jumbo Frame support. I enabled it and tested and did not notice a huge difference in data transfer rate on my LAN. I may not have had everything set up correctly, your results may vary.

Hope this helps you make a decision.

[Paul Goodwin]

Thanks so much for the info. I read virtually all of it. The Jumbo Frames thing sounds very tricky - and possibly detrimental. I'll have to see if Time Warner Roadrunner supports them and at what sizes. Other than for really big file transfers between machines on my network (which I don't do that often) it sounds like jumbo frames isn't going to do much for me.

It also looks like the RVS4000 is not what I want. The smallnetbuilder review was a very useful one-although it's 4 yrs old, it's still likely mostly valid.

I do some gaming at times and it sounded like the adjusting of frame sizes until all the devices in the path are the same can cause unacceptable latency. Now it seems that no matter which gigabit router I choose, I need to be sure I get one where I can disable the major frames process, and maybe enable it when I want to do hard drive backups across the network. Welcome to the gigabit ethernet world I guess.

The RV220W sounds like a nice machine, but is a lot more machine than I think I need for my network. I read a very detailed review of it on Amazon at:  http://www.amazon.com/gp/cdp/member-reviews/A2BBGBR6ARRJQO/ref=cm_pdp_rev_more?ie=UTF8&sort_by=MostRecentReview#R2SCJUQOKY7EN

It also sounds like it's more complex to set up than I would like to tackle. I'm a retired electrical engineer but definitely not a skilled IT person, so plug and play simplicity is important. I understand just enough to get in trouble.

Thanks again for the links. Much appreciated.

[mpyhala]

Paul,

I'm glad you found the information helpful. I agree that the RV220W is probably much more router than you need for home use. You may find that the E4200 suits your needs well:

http://www.smallnetbuilder.com/wireless/wireless-reviews/31399-cisco-linksys-e4200-maximum-performance-wireless-n-router-reviewed

I have spoken with a few people that use it and they seemed quite happy with it. It appears to have great WAN throughput and it has Gigabit ports. If you don't need wireless you can simply disable it.