In the BGP MPLS VPN network, which of the following functions should the PE equipment support ?

XZ company requires to build its network based on the modular enterprise network architecture. Z company in Shenzhen and Xi'an each 1 R & D base ; save Beijing and Shanghai have an office building ; save 23 provincial capital cities with more than 50 people in the office ; the 200 has no more than smaller cities 8 small office person ; At any given time, there are usually more than 200 marketing and technical personnel on business trips, and some of them are often located in areas lacking Internet access and can only dial in to the headquarters through the telephone network.Due to environmental and cost issues, some offices cannot access the headquarters through dedicated lines or packet-switched wide area network connections.According to these circumstances, the network module that Z company should have is _____ .

The following of GRE VPN and BGP / MPLS VPN correctly described ____ .

In the basic configuration of L2TP in independent LAC mode , the description of the name of the local end of the tunnel is correct.

In the SIP network, when the redirect server receives the session request message sent by the calling UA ,