With regard to PNNI: (multiple answer)

A.
For interoperability, PNNI standardizes how each node should perform CAC.

B.
A PTSE might be triggered when a node accepts a connection.

C.
A border node is a node that has at least one link that crosses its peer group boundary.

D.
The AESA selector octet is ignored by PNNI routing.

E.
As part of the hello protocol, a PNNI node will advertise its newest and oldest version of PNNI versions that are supported by the node.

Explanation:
Once database synchronization has occurred, further topology changes must be distributed throughout the network. PNNI does this by exchanging PNNI Topology State Packets (PTSPs), which contain one or more PNNI Topology State Elements (PTSEs). PTSPs are disseminated using a flooding mechanism and ensure that the network is updated when significant changes occur