1. Resilience and Service Protection in EPON Hesham ElBakoury Huawei Technologies Hesham.ElBakoury@huawei.com20 April 2012 IEEE P1904.1 Seminar, Prague, Czech Republic 1

2. EPON is a Universal Access Architecture All user types Residential Business Cellular backhaul All configurations SFU MDU/MTU FTTH FTTC/FTTN All Data Rates 1 Gb/s (.3ah-2004) 10/1 Gb/s (.3av-2009) 10/10 Gb/s (.3av-2009) One architecture simultaneously supports all user types, all deployment configurations, and all equipment generations on the same network!20 April 2012 IEEE P1904.1 Seminar, Prague, Czech Republic 2

3. Motivation for Protection in EPON With the increasing rate of deployments of EPON systems to support both residential and business applications, service protection becomes of paramount importance to maintain the QoS and high availability of these applications A network can offer protection by providing backup resources to be used when the primary resource fails. Survivability is property of a network to be resilient to failure Requires physical redundancy and protection switching mechanisms Survivability is a very important aspect of modern networks The ever-increasing bit rate makes an unrecovered failure a significant loss for network operators. No network-operator is willing to accept unprotected networks anymore.20 April 2012 IEEE P1904.1 Seminar, Prague, Czech Republic 3

4. EPON Failures The common EPON failures are: Fiber cut in feeder/drop fiber, which affect users connected to the given fiber trunk/branch; Failure of OLT/ONU transceivers, affecting either all or selected users; Failure of other passive optical components, e.g. Passive Splitter Combiner (PSC), connectors, splices etc. Different types of OLT/ONU failures, related with all other electronic, electric or mechanical components of these devices, including among the others, ASIC, connectors, power supplies etc. User (error Configuration) ODN, 19% 13% OLT(card & Transceiver) Platform , 7% (ITMS,IPTV, SS/IMS, etc.), 26% ONU, 35%20 April 2012 IEEE P1904.1 Seminar, Prague, Czech Republic 4

5. Failure Detection in EPON Fiber Plant monitoring using OTDR Active Monitoring Used for both fault detection and localization. Not specified by SIEPON. Transceiver Status Monitoring SIEPON provides network operators with ability to monitor major optical transceiver parameters for both OLT and ONU. Link Fault Detection BER Measurements. Failure to receive valid optical signal for more than 2ms. Loss of single REPORT/GATE messages within 50 msec.20 April 2012 IEEE P1904.1 Seminar, Prague, Czech Republic 5

6. SIEPON Protection Techniques Two types of Optical Link Protection are introduced by SIEPON: Trunk Protection Tree Protection Both OLT intra-chassis and inter-chassis (dual- homing/parenting) protection are supported. Inter-chassis communications protocol is unspecified by SIEPON. Both on-demand and automatic protection switching are supported. Both Line and Client Protection are supported. Key difference depends on whether the MAC client block uses combinatorial or sequential logic.20 April 2012 IEEE P1904.1 Seminar, Prague, Czech Republic 6

7. Line Protection In Line Protection Scheme, the entire MAC Client data path is shared between primary and backup paths. For example, queues and shaper/policer are shared between primary and backup paths. Line Protection Scheme is functionally equivalent to an implementation where a protection switch is located within an ONU ASIC containing two line interfaces20 April 2012 IEEE P1904.1 Seminar, Prague, Czech Republic 7

8. Client Protection In Client Protection Scheme, the entire MAC Client data path is fully decoupled. Upon protection switchover event, the backup path starts with clean history Client Protection Scheme is functionally equivalent to an implementation where a protection switch connects to two separate ONU/OLT ASICs, each with a single line interface20 April 2012 IEEE P1904.1 Seminar, Prague, Czech Republic 8

9. Trunk Protection Trunk Protection ONU is not protected. The OLT and trunk fiber are duplicated. Protection area Backup OLT can be in hot or cold stand-by mode Switching time must not exceed150 msec. ONU#1 2:N optical splitter PON IF PON IF OLT 1 PON IF ONU#N OLT 2 PON IF20 April 2012 IEEE P1904.1 Seminar, Prague, Czech Republic 9

10. Tree ProtectionTree Protection To balance traffic loads of different ONUs between OLT, ONU and the entire fiber plant are two OLTs, a single OLT can act as working OLT forprotected against failure. some ONUs, while simultaneously act as stand-by Only Hot Stand-by mode is supported. OLT for other ONUs. Switching time must not exceed 50 msec.20 April 2012 IEEE P1904.1 Seminar, Prague, Czech Republic 10

11. Applications of SIEPON Protection Trunk Protection Switch over time is