Question: What is a requirement for an SGSN, S-GW, P-GW, or GGSN when it supports IPv6 in the backbone network, according to standards for General Packet Radio Service (GPRS)?
Option 1: It must only use DNS-type logical names for identification.
Option 2: It shall also support IPv4.
Option 3: It can only have one IP address of type IPv6.
Option 4: It is exempt from using private address space for the backbone network.
Explanation: This answer highlights a key aspect of backward compatibility and dual-stack support in telecom networks. By requiring devices that support IPv6 to also support IPv4, the standard ensures seamless communication between newer (IPv6-capable) and older (IPv4-only) network components, facilitating a gradual transition to IPv6 without disrupting existing infrastructure.