642-437試験無料問題集「Cisco Implementing Cisco Unified Communications Voice over IP and QoS v8.0 (CVOICE v8.0) 認定」
DRAG DROP
Drag the signaling methods from the left and drop them in the correct position in the graphic on the right. Some methods are used more than once, and some methods may not be used at all.
Drag the signaling methods from the left and drop them in the correct position in the graphic on the right. Some methods are used more than once, and some methods may not be used at all.
正解：
Explanation:
The one thing that distinguishes a PRI from other interfaces is the fact that the data that is received from the PSTN on the D-channel and needs to be carried in its raw form back to the Cisco CallManager to be processed. The gateway does not process or change this signalling data, it simply passes it onto the Cisco CallManager through TCP port 2428. The gateway is still responsible for the termination of the Layer 2 data. That means that all the Q.921 data-link layer connection protocols are terminated on the gateway, but everything above that (Q.931 network layer data and beyond) is passed onto the Cisco CallManager. This also means that the gateway does not bring up the D-channel unless it can communicate with Cisco CallManager to backhaul the Q.931 messages contained in the D-channel.
http://www.cisco.com/en/US/tech/tk1077/technologies_tech_note09186a00801da84e.shtml