Frequently Asked Questions (FAQ)

1:	Is one WAN technology better than another?
A1:	There is no one WAN technology for example, ATM, Frame Relay, SMDS, IP VPN, etc. that is the best choice. As with all network design questions, the answer is "It depends." ATM is better suited for applications where a consistent QoS is required, such as supporting voice/video applications. Frame Relay is better suited for bursty data applications, such as e-mail, file transfer, or LAN-to-LAN communication not requiring a QoS Service Level Agreement (SLA) with the NSP.
2:	How is a WAN accessed?
A2:	Most WAN implementations use dedicated (DS0/DS1/DS3) access to the NSP. The access bandwidth depends on customer application requirements. For example, video conferencing requires approximately 112 K to 384 Kbps for one conversation (depending on the desired quality), whereas e-mail and other data transfers might require only 56 Kbps of bandwidth.
3:	Where do IP VPNs fit into wide area networking?
A3:	IP VPNs are a relatively new technology, and several challenges are being addressed; most notably, the requirement for QoS. Several network service providers provide this QoS for IP VPNs with an underlying ATM backbone core. IPv6 (IP version 6) is designed to address QoS in native IP networks, but has yet to gain rapid acceptance due to the wide deployment of IPv4 (IP version 4). Some network service providers do provide for IPv4/IPv6 conversion at the network access point; however, IPv6 remains to be implemented in a ubiquitous fashion.