So what? Is is a sugnificant drawback? I do not think so. Both ISL and 802.1q require special interface cards (with extended frame size), and I do not see any reason, why 26 bytes vs 4 bytes makes big difference. /May be, the only pro for 802.1q tagging is it's possible implementation on the old interface cards, which did not allowed extra 30 bytes but allowed extra 4 bytes/.
I am no saying that ISL is better tha 802.1q, but 802.1q is not much better than ISL, and (in some cases) is even worst. ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Monday, January 26, 2004 9:10 AM Subject: Re: Any 1U - 2U Ethernet switches that can handle 4K VLANs? > > ISL _DOES NOT CHANGE_ packet size. > > An 802.1q tag adds 4 bytes to the Ethernet frame. > > ISL encapsulation adds 30 bytes to the Ethernet frame. > > Steinar Haug, Nethelp consulting, [EMAIL PROTECTED]
