Usage of Internet or LAN port for exit VSCs ?

[ONVZ]

Hi all,

Equipment:

- MSM765zl v5.7.2 in 5412zl switch. MSM 430 APs on 2910alPoE switches that are directly connected to the 5412zl.

   DHCP for guest by WLC. DHCP for others by DHCP server locally or Internet router.

- We have the guest VSC going straight out of the Internet port and other VSCs out of the LAN port, e.g. to the local

   domain.

I'm having some issues, amongst other with the RF signals.

With quite a few APs the signal shows dips as bad as from 45dbm to 80dbm or the signal even temporarily disappears completely.

We had a meeting with a 3thd party today.

They stated that our configuration was not best practise.

Best practise supposedly is to have only management traffic between APs and WLC on the LAN interface, and everything else on/out off the LAN port.

I was quite surprised and, virtually, fell off my chair.

I 've seen quite some configurations where the LAN interface was well used for VSCs exits.

Is there any truth, sense or necessity in the stated best practise?

In a special situation perhaps? (which we have not I dare to say).

Thanx for any comment.