Our recent work on the regioselective synthesis of a number of heterocycles (4) prompted us to search for a simple and effi- cient reagent for this heterocyclization. We have recently achieved a facile entry to this ring system 6 (5) with the use of a well-known brominating agent, pyridine hydrobromide per- bromide, which we report here.
Voice VLAN. 1  Voice VLAN allows you to enhance VoIP service by configuring ports to carry IP voice traffic from IP phones on a specific VLAN. VoIP traffic has a preconfigured OUI prefix in the source MAC address. 2  You can configure VLANs on which voice IP traffic is forwarded.
In the case of Cisco switches (and most other Vendors), the Default VLAN is usually VLAN 1. Typically, this VLAN is only relevant on an Access port, which is a port that sends and expects to receive traffic without a VLAN tag (also referred to an 'untagged port' by other vendors).