b. In Figure 8-25, is the packet shown a transport packet or a signaling packet? c. What are the two main signaling standards in VoIP? d. What does the registrar server do? (Hint: Don’t say, “It...

b. In Figure 8-25, is the packet shown a transport packet or a signaling packet? c. What are the two main signaling standards in VoIP? d. What does the registrar server do? (Hint: Don’t say, “It registers things.”) e. What type of SIP message does a VoIP phone use when it wants to connect to another VoIP phone? f. How is this message routed to the called VoIP phone? g. Are SIP proxy servers involved during transport transmissions? Explain. h. What two types of communication does the media gateway translate between the VoIP network and the PSTN?