1. RESILIENT PACKET RING NETWORK(RPR)

2.  The nature of the public network has changed. Demand for Internet Protocol(IP)data is growing at a compound annual rate of between 100% and 800%1,while voice demand remains stable.  Over the last 10 years, as data traffic has grown both in importance and volume, technologies such as frame relay, ATM, and point-to-point protocol (PPP) have been developed to force fit data onto the circuit network  More recently, Gigabit Ethernet has been adopted by many network service providers.  Gig has shortcomings when applied in carrier networks were recognized and for these problems, a technology called Resilient Packet Ring Technology were developed.

3. Resilient Packet Ring Technology (RPR).  Resilient Packet Ring (RPR) is an emerging network architecture and technology designed to meet the requirements of a packet-based metropolitan area network(MAN).  Neither SONET nor Ethernet is ideal for handling multimedia traffic on a ring network  Resilient Packet Ring (RPR) is a network topology being developed as a new standard for fiber optic rings  It works in point to point,ring or mesh networks.  Uses MAC layer tech.(Standardized as IEEE 802.17)

4. Resilience proactive span protection automatically avoids failed spans within 50 ms. Services support for latency/jitter sensitive traffic such as voice and video.support for committed information rate (CIR) services. Efficiency spatial reuse:Unlike SONET,bandwidth is consumed only between the source and destination nodes.packets are removed at their destination,leaving this bandwidth available to downstream nodes on the ring. Scalable supports topologies of more than 100 nodes per ring. RPRs Key features

5.  RPR uses a dual counter rotating fiber ring topology  Both rings inner and outer are used to transport working traffic between nodes.  By utilizing both fibers RPR utilizes the total available ring bandwidth, fibers are used to carry control messages  Control message flow in the opposite direction of the traffic that they represent.  using bandwidth-control messages It has ability to differentiate between low-and high-priority packets nodes have the ability to transmit high-priority packets before those of low priority RPR Operation

6. RPR nodes also have a transit path It has a transit buffer capable of holding multiple packets Nodes with smaller transit buffers use bandwidth-control messages RPR Media Access Control(MAC). one of the basic building blocks of RPR. responsible for providing access to the fiber media. can receive,transit and transmit packets.

7. Receive Decision TX BW Control Transit Path To Host Topology From Host Protection TX BW To Host From Host From West Fiber To West Fiber To East Fiber MAC Block Diagram

8. Receive Decision Every station has 48 bit MAC address. MAC will receive any packets with a matching destination address MAC receive both unicast and multi cast packets there are also control packets that are meant for the neighboring node these packets do not need a destination or source address. Transit Path Nodes with non matching destination address are allowed to circulate RPR packets are only inspected for a matching address and header errors Transmit and Bandwidth Controls RPR MAC can transmit both high-and-low priority packets for low-priority packets bandwidth algorithm controls whether a node is within its negotiated bandwidth allotment bandwidth-control algorithm

9. Protection RPR has the ability to protect the network from single span failures. Wrapping Nodes neighbouring the failed span diverts the packet by wrapping traffic around to the other fiber span Topology Discovery: RPR has a topology discovery mechanism Physical Layer RPR packet can be transported over both SONET and Ethernet physical layers SONET physical layer offers robust error and performance monitoring. when using SONET physical layer,RPR can be carried over dark fiber.

10. Comparison between Gigabit Ethernet and RPR GIGABIT ETHERNET RPR Enterprise-class equipmentCarrier-class equipment Provides Data service onlyData, circuit or video service Works in Point-to-point or mesh topology(No Rings) Point-to-point,linear,ring,or mesh topology Protection in 50 secondsProtection in 50 milliseconds or less simple managementcomplex management Has Limited scalabilityContains 254 nodes per ring,multiple rings

11. Comparison between SONET/SDH and RPT SONET RPR Has Manual topology ConfgAuto-topology config. 16 nodes per ring254 nodes ring management bandwidth is fixed Time division multiplexing Management bandwidth used as needed Statistical multiplexing Has Manual provisioning of bandwidth and routes Manual or dynamic provisioning No service class awarenessDifferentiated services in eight classes Fixed direction traffic routingLeast-cost traffic routing

12. Technical aspects of RPR Multicast packet can be transmitted around the ring and can be received by multiple nodes. Mesh topologies requires multicast packets to be replicated over all possible paths, wasting bandwidth. Spatial Reuse RPR has the ability to switch traffic over multiple spans of the rings simultaneously Bandwidth on a particular span between ring nodes is utilized async. Fairness most important features in carrier-class networks RPR protocol can guarantee fairness across the metropolitan network.

13. Quality of Service is required in order to let a carrier effectively charge for the services it provides. ATM promised to deliver multiple services due to its rich QoS set. several parameters govern the characteristics of a delivered service Service availability, delay, delay variation and RPR Market Development ISP Network RPR solutions are helping ISPs to deliver reliable internet services (such and IP and video) and address the growing bandwidth service requirements for the next generation intra-point of presence (POP), exchange point, and server frame/storage applications.

14. Regional Metro Network. RPR regional metro solutions are available for transport over dark fiber, over wavelength division multiplexing (WDM), and over SONET cable, and enterprise/campus MANs Metro Access Networks provide direct Ethernet connectivity for multi-tenant/multidwelling customers and edge programmability.

15.  Packets-optimized, Layer-1 independent protocol that allows transport, switching and routing functions in a single platform.  Provides Differentiated data services, with advanced QoS mechanisms.  Provides Point-to-point and multipoint services. Benefits of RPR

16.  Provides End-to-end networking through a standard,  Maximum utilization of the fiber bandwidth  Faster deployment of services.  Ease of provisioning and management of the ring.

17. Main objectives of RPR  enable a true alternative to SONET  providing carriers with resiliency  fast protection and restoration and performance monitoring  designed to combine SONET strengths of  high availability  reliability  and TDM services support,  superior bandwidth utilization and  high service granularity characteristics. Conclusion

18.  RPR is  reliable,  efficient  promoted and standardized by industry leaders- as well as by innovative startup companies,  positioned to take a major role in deployment of next generation carrier-class networks.