6.7 Resilient Packet Ring 421 connection. T-MPLS reuses the architecture of MPLS and simplifies it for transport. It adds features to support bidirectional connections, since MPLS is a unidirectional technology. Since T-MPLS connections are expected to have very long lifetimes, T-MPLS has protection switching and operations and management not found in ordinary MPLS (see Section 9.3.4 on protection switching). Due to concerns over the compatibility of Transport MPLS with MPLS, development of T-MPLS has been halted and work on a new MPLS has begun, called MPLS-Transport Profile (MPLS- TP). This new development will likely incorporate some of the aspects of T-MPLS. 6.7 Resilient Packet Ring Resilient Packet Ring (RPR) is a packet-switched ring network that transports data packets such as IP packets. It has application as a metropolitan- or wide-area net- work. RPR provides different services. It has guaranteed bandwidth to emulate constant-bit-rate, low delay service, and it has fair access for best-effort service. The ring network topology is resilient to failures, and in particular it remains connected after single-link or single-node failures. The RPR failure recovery mechanism is dis-