Carrier Grade Ethernet. Ethernet in service provider networks, MAN/WAN

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1 Carrier Grade Ethernet Ethernet in service provider networks, MAN/WAN

2 Carrier grade The term Carrier Ethernet implies that Ethernet services are carrier grade. Carrier grade is a system that is extremely reliable, well tested and proven in its capabilities. Carrier grade systems are tested and engineered to meet or exceed five nines (99,999%) high availability, and provide very fast fault recovery through redundancy.

3 Attributes and challenges to a carrier Ethernet Defined by the Metro Ethernet Forum (MEF)

4 Attributes and challenges to a carrier Ethernet Standardized services Enables a service provider to deliver a host of both packet and traditional TDM multipoint services Scalability Providers require that the network scale to support hundreds of thousands of customers Reliability Carrier Ethernet must match the performance level seen by traditional WAN technologies Service management Service management systems and monitoring is required Quality of service Service providers must be able to offer customers differentiated levels of service to match application requirements

5 IEEE 802.1Q Virtual LAN (VLAN) Used to separate traffic in a LAN Identified by a Q-tag on the Ethernet frame Inadequate when service providers attempt to deliver Ethernet services to multiple end users over a shared network infrastructure Enterprises need to control their own VLANs Overlapping issues in the service provider network 12-bit tag (4096 Q-tags) scalability issue

6 IEEE 802.1AD Provider Bridges (PBs) An S-tag is added to the customer s Ethernet frame The S-tag is used to identify the service in the provider network, while the customer s VLAN ID (C-Tag) remains intact Same scalability issues as VLAN (12-bit tag) Customer and provider networks appear as one large network

7 IEEE 802.1AD Provider Bridges (PBs)

8 IEEE 802.1AH Provider Backbone Bridges (PBB) Adds a new header to the customer s Ethernet frame backbone source and destination MAC address, backbone VLAN ID (B-Tag), backbone service ID (I-Tag) 24-bit I-Tag (16 million services) no scalability issue PBB provides clear separation between the PB network and the PBB network because each has a dedicated set of MAC addresses Security is improved because the PBB switches in the core are no longer inspecting the PB MAC headers

9 IEEE 802.1AH Provider Backbone Bridges (PBB)

10 Traffic Engineering Traffic engineering is made possible with PBB traffic engineering (PBB-TE) IEEE 802.1Qay MAC forwarding tables are populated via the management or control plane instead of the traditional flooding and learning techniques. Creates a point-to-point connection-oriented forwarding mode

11 OAM in Ethernet OAM Operations, Administration, and Maintenance Traditional Ethernet does not have OAM functionality required by networks in MAN and WAN environments OAM is important for Ethernet to be carrier grade Two main areas of OAM: fault management and performance monitoring

12 Fault Management Ensures that when a defect occurs in the network, it is reported to the operator, who can then take the appropriate action Fault detection Continuity check messages (CCMs) are sent from source to destination node at periodic intervals Fault verification Loopback messages (LBMs) and loopback reply (LBR) are used during initial setup or after a fault has been detected to verify that the fault has occurred between two endpoints. Fault isolation Linktrace messages (LTMs) and linktrace reply (LTR) is used to isolate the fault. Fault notification AIS packets are sent to the service endpoints to alert the operator of a fault in the network

13 Performance monitoring Performance in Ethernet networks varies due to queueing and congestion. As a result, carrier Ethernet networks require advanced performance monitoring Frame loss ratio Calculates frame loss by sending transmit and receive counters within the CCM for dual-ended measurements Frame delay Calculates latency in the network Frame delay variation Calculates jitter