Date: 25-Nov-2009 URL: www.sun.com/products/networking/ethernet/jumbo/index.html

Jumbo Frames

Jumbo Frame support is designed to the enhance Ethernet networking throughput and significantly reduce the CPU utilization of large file transfers like large multimedia files or large data files by enabling more efficient larger payloads per packet. By sending larger payloads per packet, fewer packets need to be routed, reducing the overhead on the CPU and potentially improving networking throughput.

Jumbo Frame support in Sun's Gigabit Ethernet Network Interface cards allows the sending and receiving of jumbo frame size packets which are up to 6 times the size of standard Ethernet packets. Jumbo Frame delivers up to 9216 byte packets instead of a 1522 byte packet for standard Ethernet, which consists of a 1500 byte payload + 14 bytes for header + VLAN tag 4 bytes + CRC 4 bytes.

Highlights

Key Features:

Supports up to 9K bytes MTU (Maximum Transfer Unit)
VLAN containment (MTU specified in a per VLAN basis in addition to per card basis)
Jumbo Frame, once set, remains persistent through reboots
Jumbo Frame can be disabled on the fly without reboot

The Network Interface Cards (NICs) listed below will support Jumbo Frames:

Note: The following NICs do not support Jumbo Frames:

Crypto Accelerator X4011A/4012A
cPCI Gigabit Fiber X1261A

Jumbo Frames Software Downloads

Jumbo Frame support requires an update to the NIC driver. The software driver "ce" patches are available on SunSolve under the following patch numbers. Select the patch appropriate to the version of Solaris OS used.

A User's Guide for Jumbo Frames can be found at: http://www.sun.com/products-n-solutions/hardware/docs/Network_Connectivity/Sun_GigaSwift_Ethernet/index.html