27 Mar
2007
27 Mar
'07
10:42 a.m.
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