What is JUMBO frame?
zathe...@gmail.com
accept JUMBO frame, when an ethernet frame size (maximum) can never
exceed 1522 as per IEEE 802.Q ?
Albert Manfredi
wrote:
> What is actually a JUMBO frame? Does it standardised? How a L2 switch
> accept JUMBO frame, when an ethernet frame size (maximum) can never
> exceed 1522 as per IEEE 802.Q ?
That's because jumbo frames are not standard.
However, if you use the "type" format, there's no reason in principle
why the frame size can't grow beyond 1522 bytes. Of course, all
switches in the path must be aware of the possibility of these jumbo
frames.
Bert
PranavT
wrote:
> On Dec 28, 11:34 am, "zatheesh...@gmail.com" <zatheesh...@gmail.com>
> wrote:
>
> > What is actually a JUMBO frame? Does it standardised? How a L2 switch
> > accept JUMBO frame, when an ethernet frame size (maximum) can never
> > exceed 1522 as per IEEE 802.Q ?
>
payload. Conventionally, jumbo frames can carry up to 9,000 bytes of
payload. Why 9000? because ethernet uses a 32 bit CRC that loses its
effectiveness above about 12000 bytes.
Many Gigabit Ethernet switches and Gigabit Ethernet network interface
cards support jumbo frames. You can partition a logical network in
which systems can exchange Jumbo Frames and mark them with IEEE 802.1Q
virtual LAN tags. The extended frames will be transparent to the rest
of the network.
Adapters that implement IEEE 802.1Q can support different Ethernet
frame sizes for different logical network interfaces. For example, a
server could communicate with another server using Jumbo Frames while
communicating with clients sitting on another VLAN or IP subnet using
standard Ethernet frames - all via the same physical connection.
pranav tailor
Rick Jones
There is no "de jure" standard for the size of a "jumbo frame" as the
IEEE has not seen fit to create one. One can argue though that the
"de facto" standard for the jumbo frame is such that it results in an
IPv4 MTU of 9000 bytes or more based on that being what Alteon used in
their GbE NICs which IIRC were among if not the first to have a "jumbo
frame" in the Ethernet space.
rick jones
(At least they were the first place I can recall seeing jumbo frames
in an Ethernet interface)
--
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Stephen
<rick....@hp.com> wrote:
>zathe...@gmail.com <zathe...@gmail.com> wrote:
>> What is actually a JUMBO frame? Does it standardised? How a L2
>> switch accept JUMBO frame, when an ethernet frame size (maximum) can
>> never exceed 1522 as per IEEE 802.Q ?
>
>There is no "de jure" standard for the size of a "jumbo frame" as the
>IEEE has not seen fit to create one. One can argue though that the
>"de facto" standard for the jumbo frame is such that it results in an
>IPv4 MTU of 9000 bytes or more based on that being what Alteon used in
>their GbE NICs which IIRC were among if not the first to have a "jumbo
>frame" in the Ethernet space.
>
Agreed, although i have seen "jumbo" on 100 Mbps as well, although
cannot remember where, and it has spread to 10G as well.
A Cisco Cat 6500 could even have more than 1 different jumbo limits,
just on different blades if you had various vintages of equipment.
and the telecomms suppliers do not agree about 9000 bytes:
- some Marconi SDH kit calls 4000+ bytes "jumbo".
- and DWDM kit often works happily at 64 Kbytes since they dont even
worry about packet boundaries.
and then there is "baby jumbo" which is more than standard 1514 /
1518, but usually less than 1600 or 2000 bytes.......
>rick jones
>
>(At least they were the first place I can recall seeing jumbo frames
>in an Ethernet interface)
--
Regards
stephe...@xyzworld.com - replace xyz with ntl