The Cisco ONS is interoperable with our existing Cisco ONS UPSR architecture and it also gives us 16 rings of completely interoperable ONS. BLSR,Bi-directional Line Switched ring. There are two types of BLSR deployed in various networks. i. 2-fiber BLSR ii. 4-fiber BLSR. How is Bi-directional Line Switched Ring (SONET) abbreviated? BLSR stands for Bi-directional Line Switched Ring (SONET). BLSR is defined as Bi-directional.

Author: Arashikazahn Zulkibar
Country: Lithuania
Language: English (Spanish)
Genre: Literature
Published (Last): 4 April 2007
Pages: 152
PDF File Size: 18.57 Mb
ePub File Size: 5.33 Mb
ISBN: 500-1-78011-471-2
Downloads: 86326
Price: Free* [*Free Regsitration Required]
Uploader: Shaktisar

Eight free slots exist. MPLS based networks use fast re-route blr its network resiliency mechanism. Intermediate nodes serve these shorter regional connections. Other terms used to describe link aggregation include IEEE The traffic travels in reverse rung on the protect bandwidth until it reaches its destination node. OC-3 optics provide remote switch connectivity to a host TR switch. Because they allow span switching as well as ring switching, four-fiber BLSRs increase the reliability and flexibility of traffic protection.

Plan your fiber connections and use the same plan for all BLSR nodes.

The p-cycle technique is bls on the property of a ring to protect not only its own links, but also any possible links connecting two non-adjacent ring nodes called chordal links. At the time of ring switching, those channels carrying service traffic are switched to the channels that carry the protection traffic in the opposite direction.

Notice that all that is needed for this circuit to be operational is the ring1 fiber unidirectional path. At that point, traffic is switched back to the working bandwidth.

With multiple nodes, a span rig is a coordinated series of upgrades on all nodes in the ring or protection group in which traffic carried at a lower OC-N rate is transferred to a higher OC-N.

NutraT line 14 September at Node A will therefore receive its signal from B on ring2. Wish you more success. This is really an interesting topic. When the physical link fails, the upstream node switches traffic to the virtual link so that data continues to flow with a ringg disruption.


This is the most robust blxr architecture. Although it is not strictly considered as one of the mesh-based ring protection techniques, its usage of a loopback operation is similar to the APS operation in rings to switch the signal from working to the redundant capacity.

Unknown 31 August at If a failure occurs on the primary path, traffic switches to the second circuit path. For example, if you need to drop more than DS-1s or 96 DS-3s the maximum that can be aggregated in a single nodeyou can link the nodes but not merge multiple nodes into a single ONS In a ring switch, traffic is routed to the protect fibers throughout the full ring.

Due to its efficiency in protection, BLSRs are widely deployed in long haul and interoffice networks, where the traffic pattern is more distributed than in access networks. Protection architectures like Path protection and Link protection safeguard the above-mentioned networks from different kinds of failures.

Chapter 9, SONET Topologies

Visit at Crazy Video Hub. There are two types of BLSR deployed in various networks. This flexibility in the reuse of rign is one of the major advantages of a BLSR. For Exerciser request, extra traffic is allowed to exist on the protection channels. In the example, each remote switch requires eight DS-1s to return to the host switch. You can link nodes with OC or OC fiber spans as you would link any other two network nodes. Protection against fiber cuts and node failures is done by reserving bandwidth on the ring strictly for protection.

To illustrate the protection switching in a BLSR assume the traffic patter shown in figure 4. This is because, only the protection channels along one span are used for each span switch.

Link protection

In Link protection, the end nodes of the failed link initiate the protection. Leslie Lim 7 July at Hoping to read more post from you in the future.


Fiber 1 carries the circuit to Node 3 the original routing destination. Rkng the case of adjacent node traffic the capacity advantage of the BLSR grows linearly with the number of nodes, however in most cases the traffic will likely resemble a distributed logical mesh still providing a capacity advantage but not quite as extreme as in the adjacent node traffic case.


Slot 5 west and Slot 12 east carry the working traffic. In a BLSR, every link can carry both the working and backup traffic at the same time and hence does not bls backup links.

Posted by Shankar BLR at The same signal is also sent on the protect traffic path through Node ID 3. For purposes of discussion the outer fiber loop is referred to as ring1 and the inner fiber loop blar referred to as ring2. Both the fibers carries service and protection channels.

The BLSR will not function if working and protect cards are interconnected. The Cisco Blse Controller CTC circuit routing routines calculate the “shortest path” for circuits based on many factors, including requirements set by the circuit provisioner, traffic patterns, and distance. In this example a circuit is to be set up between nodes A and C. Because each traffic path is transported around the ribg ring, UPSRs are best suited for networks ting traffic concentrates at one or two locations and is not widely distributed.

Working traffic STSs 1 – 24 travels in one direction on one fiber and in the opposite direction on the second fiber. This system is also known as two fiber multiplex-section shared protection ring. In the case of a link or network failure, the simplest mechanism for network survivability is automatic protection switching APS.