Router Charts

Router Charts

Router Ranker

Router Ranker

Router Chooser

Router Chooser

NAS Charts

NAS Charts

NAS Ranker

NAS Ranker

More Tools

More Tools

LAN & WAN Features

Introduction

Updated 11/2/2007 - Corrected info regarding UDP DF handling.

A different kind of Jumbo

In many of our reviews, we comment on a device's support for gigabit Ethernet, as well as whether it supports jumbo frames. But what are jumbo frames and why should you care about them? In basic terms, a jumbo frame is any frame larger than a standard Ethernet frame. Their main value is that they can dramatically improve network performance by raising effective bandwidth.

Jumbo frames can be a bit of a challenge, though, as there are multiple sizes, interpretations, and technologies, making it difficult to fully understand and leverage their value, as well as fully integrate jumbo frame devices into your network. The goal of this article is to explain jumbo frames and help you determine if and how you can use jumbo frames in your network.

Gigabit Ethernet

An important fact is jumbo frames are not supported at speeds less than 1000 Mbps. There are some exceptions, with larger frame sizes possible on FDDI, POS, and Fiber Channel connections, but for typical small network purposes, you're going to need equipment with gigabit Ethernet interfaces that support jumbo frames to see network gains from larger frame sizes. We've covered the details on gigabit Ethernet pretty thoroughly in our Gigabit Ethernet Need to Know a few years back; it's an excellent discussion on the facts and details regarding gigabit network speeds.

Gigabit Ethernet interfaces are now common on PCs, NAS devices, switches and routers. Not all gigabit Ethernet interfaces support jumbo frames, though, and since there isn't a standard for jumbo frames, there are different sizes.

For example, I have a laptop and desktop PCs with gigabit Ethernet NICs (Network Interface Card). The desktop gigabit Ethernet NIC allows jumbo frame configuration, whereas my laptop NIC supports gigabit Ethernet, but does not support jumbo frame configuration. Figure 1 is a screen shot of the configuration options I have for jumbo frames on my desktop PC, showing the different sizes of jumbo frames it supports.

NIC jumbo properties

Figure 1: Properties of a NIC supporting jumbo frames

As you can see, my desktop PC NIC supports jumbo frame sizes of 16128, 4088, and 9014 bytes. Based on the 9014 byte supported size, it appears my desktop PC is one of those interpretations that doesn't consider the 4 byte CRC header as part of the countable frame size, a detail I'll cover in the "What is a Jumbo Frame?" section.

More LAN & WAN

Top Performing Routers

AC3200
AC2350
AC1900
AC1750
AC1200

Top Performing NASes

NoRAID
RAID1
RAID5

Over In The Forums

I don't know if i missed something, but here the topo: i have dns filter enable with global profile set to opendns and some mac addresses using a different dns filtering...
Hello, I recently downloaded the rmerlin firmware. How does one install firmware from multiple zip files? Also, it seems that the RT-AC66U_3.0.0.4_376.49_X.zip files have x=0, x=2, x=4 and x=5. No...
I recently purchased an X99-Deluxe MB, and it has 2 1GB LAN ports. One of the options in the settings is to set these up for LAN teaming. Is there...
I´m not sure where the problem is but guess it have to do with Quentenna drivers or my wifi client. This problem with lag only appear on 5Ghz wifi never...
Highlights of this release: Official support for the RT-N16 is being dropped. This last model based on SDK5 requires too much efforts to maintain. New features such as the...