Circuit Emulation Over Transport BOF (ceot) Tuesday, December 12 at 1700-1800 ================================= CHAIRS: Luca Martini Chris Liljenstolpe DESCRIPTION: SPs are focused on providing services for customer transport of layer 1 and layer 2 (bit-based and frame-based) payloads over a unified infrastructure. These services, often referred to as transparent transport, includes the transport of Ethernet, ATM and Frame Relay as well as methods for transporting time division multiplexed (TDM) digital signals (SONET circuit emulation) over a packet-oriented network. The Objectives of this BOF are : Present some problems to be solved: Layer 1/2 Circuit emulation service, and Legacy core circuit transport across new transport technologies. Assess the viability of of pursuing standardization work within the IETF. Discuss , and obtain agreement on the two proposed WG charter. READING MATERIAL: draft-martini-l2circuit-trans-mpls-04.txt draft-kompella-mpls-l2vpn-02.txt draft-stdenis-ms-over-mpls-00.txt draft-malis-sonet-ces-mpls-01.txt draft draft-white-sonet-format-rtp-00.txt draft-boyle-sts-ip-00.txt AGENDA: * Agenda Bashing - co-Chairs ( 5 minutes ) * Legacy Circuit Emulation over transport. ( 10 minutes ) * Layer 2 VPNs service over transport. ( 10 minutes ) * CEOT Charter review ( 25 minutes ) * Where do we go from here. ( 10 minutes ) ------------------------------------------------------------------------------- Background Service providers (SP) offering digital transport services are seeking to unify transport of multiple services across a common packet switched network. Examples of digital transport services include transport of IP packets, Ethernet frames, ATM cells, Frame Relay frames, and time division multiplexed (TDM) digital signals. In the past this has been achieved by defining interworking functions between each type of digital transport service and the transport technology used in the packet switch network. The benefit to the service provider is that all aspects of the service including quality of service (QoS), encapsulation of protocol data units (PDU), and management and control interworking function. The downside is that this approach is often complex, time consuming, and costly to implement. An alternative approach is to use tunnels to transparently transport digital services across a packet switched network. There are many proprietary service specific implementations in the market that use this approach. Under this approach no strict interworking function is required between the digital transport service and the transport technology used in the packet switch network. The packet switched network can transparently transport PDUs for any service without knowledge of the service being transported. Transparent Transport The basic idea behind transparent transport is to create "virtual wires" across a packet switched network by encapsulating service- specific Packet Data Units ( PDUs) arriving at an ingress logical port and transporting them across a tunnel to an egress device. At the egress device the encapsulation header is extracted and used to determine the outgoing logical interface. The PDUs are then sent on the egress logical interface. From the customer perspective the virtual wire is perceived as an unshared connection using the native digital service transport format. The customer is not exposed to the underlying technology used in the packet switched network. The service provider is able to offer multiple services across a common packet network without complex interworking functions. Transparent transport requires the edge devices providing service interfaces to use common service-specific techniques for encapsulating PDUs, passing service status information, and performing link monitoring across the tunnel. Common Status and Control Plane Some form of network control is required to create and manage tunnels across the packet switched network and coordinate service-specific information between the edge devices. This control may be provided through a command line interface, a network management protocol, or a dynamic signalling or routing protocol. The protocols used for tunnel management depend on the type of packet switch network deployed by the carrier. For example, LDP or RSVP-TE may be used to create and manage tunnels across a packet switched network based on MPLS. New protocols or modifications to existing protocols are required to coordinate service-specific information between edge devices. More than one protocol may prove viable for coordinating service-specific information. For example, BGP or LDP may be modified for this purpose. Purpose The purpose of the BOF is to assess the viability of pursuing standardization work within the IETF for these new transport technologies. If this work is determined to be viable, a CEOT working groups is envisioned to carry out the process. The working group will focus on development of a common status and control plane for the end to end tunnel, and common techniques for encapsulating service-specific PDUs. This BOF will focus on discussion of the CEOT WG , and its requirements. WG Preliminary Objectives Specify statistics and other network management information needed for tunnel operation. For example, to be able to determine when a circuit's up/down state has changed. Specify the mechanisms that are needed to distribute the end to end setup information for the circuit being transported. Specify the mechanisms that will service providers to extend the emulated circuit to be transported across multiple service provider networks ( NNI interface ). Specify the security mechanisms to be used to protect the control of the CEOT technology at the NNI interface. Specify end to end circuit status signaling methods. Specify methods for integrating end to end tunnel signaling information, and diffserv information with the transporting network. Specify methods to communicate timing across the transport network.