So the most common real world example in NZ is UBS. Take the subscriber's 1500byte packet, add a PPP header, an extra IP and UDP header (for L2TP) and two MPLS headers (inside TNZ's netowrk) and jumbo frames look pretty useful. As alluded to below, 802.1q and especially stacking of vlans are strong reasons, even more so if transported over MPLS (Martini/VPLS). Jono
---- Original Message ---- From: nznog(a)daork.net To: NZNOG(a)list.waikato.ac.nz Subject: Re: [nznog] jumbo frames Date: Wed, 28 Mar 2007 15:04:56 +1200
MPLS. VLANs. L2TP with 1500byte payloads.
etc.
On 28/03/2007, at 3:01 PM, Ian Batterbee wrote:
Has anyone got any real world experience of the usefulness of jumbo frames on ethernet (ie, MTU > 1500 bytes). A number of 1000mbps interfaces support it, but it seems to be that it would only be useful if jumbo frames were supported and enabled on all equipment between the sending NIC and final IP destination, so I'm struggling to see how enabling it in just say the core of a network would be all that helpful.
_______________________________________________ NZNOG mailing list NZNOG(a)list.waikato.ac.nz http://list.waikato.ac.nz/mailman/listinfo/nznog
!DSPAM:22,4609daac107231355811551!
_______________________________________________ NZNOG mailing list NZNOG(a)list.waikato.ac.nz http://list.waikato.ac.nz/mailman/listinfo/nznog
I've been surprised at how many fairly stupid 10/100 switches (and smarter devices that will do 802.1q but are configured not to) will happily pass fully laden 802.1q encapsulated packets. I haven't really tried to find out how big a packet they will actually take, but it's at least 1504 bytes (plus MAC header etc). -- don Jonathan Woolley wrote:
So the most common real world example in NZ is UBS. Take the subscriber's 1500byte packet, add a PPP header, an extra IP and UDP header (for L2TP) and two MPLS headers (inside TNZ's netowrk) and jumbo frames look pretty useful.
As alluded to below, 802.1q and especially stacking of vlans are strong reasons, even more so if transported over MPLS (Martini/VPLS).
Jono
participants (2)
-
Don Stokes -
Jonathan Woolley