Vlan trunking process/fast switched?

[howard.cisco]

I am designing a net to carry internet traffic, voip traffic and vpn traffic. I am considering using single handed 3620 into a 2900xl to take the feeds. I heard from a cisco se a few months ago that some vlan trunking can end up being process switched. Could you tell me if isl and .1q are process or fast switched and if there are any restrictions.

I ask this because I recently experienced 30% process switched on a 2620/2900xl with voip traffic and 80% cpu.

[smalkeric]

The only thing that a trunk port does that another port does not is encapsulation. This is done via hardware, and is outside the realm of the normal switching processes. Otherwise, its like any other port.

[srittenberg]

80% cpu ultilization should be fine if it's not constant. isl is Cisco only, dot1q is IEEE standard. If you have a fixed vendor enviroment, you need to use dot1q.