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A heuristic routing algorithm for network coding aware 1+1 protection route design for instantaneous recovery

This paper proposes a heuristic routing algorithm to design instantaneous recovery protection routes for all possible source destination pairs by provisioning network coding (NC) based 1+1 protection technique. We consider a static routing problem in networks where each node has the coding capability, and the exact traffic demand matrix is given. In the proposed heuristic algorithm a network with N nodes is divided into N scenarios, where each node is chosen as the common destination and k nodes among the remaining ones are the sources, where 2 ≤ k ≤N-1. By dividing the network into several scenarios with k sources and a common destination (k S D), all the possible source destination pairs, according to the given traffic matrix, are considered. It was reported that a mathematical programming approach to determine NC based 1+1 protection routes for any kSD scenario is an intractable problem for large k values. In the proposed heuristic algorithm we tackle this intractable problem by choosing either two or three sources out of k sources at a time according to the largest effective gain first policy, and then routing is assigned to the selected 2SD or 3SD scenario by using our developed mathematical models. The largest effective gain first policy ensures the best possible resource saving for each of the selected 2SD or 3SD scenario. We compare the total path costs of NC based 1+1 protection for all possible source destination pairs, obtained by our proposed heuristic algorithm, with that of the conventional 1+1 protection technique (without NC). Numerical results observes that almost 15% resource saving is achieved in our examined networks.

Load-Balanced Shortest-Path-Based Routing without Traffic Splitting in Hose Model

Smart OSPF (S-OSPF), a load balancing, shortest-path-based routing scheme, was introduced to improve the routing performances of legacy networks running OSPF with known traffic demands. S-OSPF distributes traffic from a source node to neighbor nodes, and, after reaching the neighbor nodes, traffic is routed according to the OSPF protocol. However, in practice, exact traffic demands are difficult to obtain, and most routers will not be able to handle the complexity of determining and implementing uneven traffic distributions with any form of precision. This paper investigates non-split S-OSPF with the hose model for the first time; its goal is to minimize the worst-case network congestion ratio. In this model, traffic from a source node to a destination node is not split over multiple routes, in other words, it goes via only one neighbor node to the destination node. The routing decision problem with the hose model is formulated as an integer linear programming (ILP) problem. Since it is difficult to solve the ILP problem in practical time, this paper proposes a heuristic algorithm. In the routing decision process, the proposed algorithm gives the highest priority to the node pair that has the highest product of ingress and egress traffic, and enables a source node to select the neighbor node that minimizes the maximum link utilization over all links for the worst case traffic condition specified by the hose model. We compare non-split S-OSPF to split S-OSPF and classical shortest path routing (SPR). Numerical results show that the non-split S-OSPF scheme improves routing performance versus classical SPR and is comparable to the split S-OSPF scheme for larger networks.

Differential delay aware instantaneous recovery scheme with traffic splitting

Summary This paper proposes a differential delay aware instantaneous recovery scheme with traffic splitting, in order to tackle multiple link failures, for networks with the coding capability. In the proposed scheme, traffic at the source is split into K equal parts and sent through K working paths. P protection paths carry encoded traffic created from the K split parts at the source. In order to recover from any t failure(s), where 1≤t≤P, the destination node has to buffer the remaining (K + P − t) parts, until the part experiencing the longest delay reaches the destination. The amount of memory buffers depends on the maximum allowable differential delay Δ, the highest difference of delays of any two among the (K + P) disjoint paths, supported at the destination. A large value of Δ increases the amount of required memory buffers, which negatively affects the achievable resource saving because of splitting. We thoroughly investigate how routing with splitting is influenced with respect to Δ, encoding/decoding costs, optical interface rates, buffering costs, the number of protection paths, the number of nodes in the network, and the minimum number of adjacent nodes. The path setup, encoding, synchronization, and merging (decoding) operations are discussed in order to support the proposed scheme. Copyright

A heuristic routing algorithm with erasure correcting code based instantaneous recovery technique

This paper proposes a heuristic routing algorithm to design routes for all possible source destination pairs by provisioning erasure correcting code based instantaneous recovery technique with optimal traffic splitting, which was addressed for a source destination pair in a prior work. We consider a static routing problem in networks having the coding capability. When the links in a network have finite capacities, assigning routing for all possible source destination pair by using this instantaneous recovery technique are mutually dependent, and this issue was not addressed. For the route designing purpose, one need to check routing for exponential number of traffic splitting number combinations. If the number of combinations to be considered, which equals the multiplication of each individual maximum possible traffic splitting numbers of all pairs considered, becomes extremely large obtaining a routing solution within a practical time is not possible. In order to achieve a routing solution within a practical time, the proposed heuristic algorithm gives highest priority to the pair either with the largest cost or with the largest resource saving effect. For all source destination pairs the total path costs of implementing erasure correcting code based instantaneous recovery technique, and conventional 1+1 protection technique are computed. Almost 20% resource saving w.r.to 1+1 protection is achieved in our examined networks.

A hybrid scheme for instantaneous recovery route design with two different coding aware scenarios

In order to reduce the required backup resources for 1+1 protection, while maintaining its instantaneous recovery advantage, two coding aware scenarios were presented, namely the traffic splitting (TS) scenario and the two sources and a common destination (2SD) scenario. Coding based 1+1 protection route design for all possible source destination pair by utilizing TS and 2SD scenarios, individually, were addressed in previous works. In those works about 15% (for 2SD) and 20% (for TS) resource saving were reported. In theory, maximum possible resource saving for 2SD scenarios is about 25% and that of for TS scenarios is about 50%. This paper proposes a hybrid scheme for coding based 1+1 protection route design for all possible source destination pairs, where the TS and 2SD scenarios are used intelligently according to the largest effective gain first policy. We evaluate our proposed scheme in several fixed network topologies. Numerical results observe that our scheme with both scenarios achieves about 26% resource saving, it is 7% higher than the worst cases when TS and 2SD scenarios are individually used in route design.

Automatic Construction of Name-Bound Virtual Networks for IoT

In this paper, we propose a mechanism for autoconfiguration of name-bound virtual networks (NBVNs) for Internet of Things (IoT). Some IoT standardization groups have defined APIs for IoT device communications, in which they indicate the correspondent nodes and resources by names. However, current technologies for the construction of Virtual Networks (VNs) rely on VLANs, IP routing, and OpenFlow control, thus they do not provide a name-based solution. Our proposal fills this gap. We first define business players that construct and use the NBVNs. They are Application Service Provider (ASP), Virtual Network Operator (VNO), and Infrastructure Provider (InP). We then specify the roles of ASP/VNO/InP, including the tasks that must be performed by their managers, and the required interactions for the purpose of autoconfiguration. Subsequently, we describe the system we developed to implement the operations of ASP/VNO/InP and thus construct NBVNs automatically. For each NBVN, the required IPv6 addresses are automatically allocated and assigned to the network nodes, including the IoT devices. Moreover, data forwarding and name resolution mechanisms are also configured automatically. Thus, the proposed system constructs area-and/or time-bound VNs for offering network services to event-centric IoT applications, such as outdoor concerts and sporting events. Finally, we demonstrate that the constructed NBVNs are capable to configure thousands of addresses and name entries within a minute, thus IoT devices can communicate among them by using their correspondent node names instead of their addresses. Moreover, both ASP and VNO can operate the servers, switches, and routers pertaining to the NBVNs by also using their names.

Route advertisement policies for border gateway protocol with provider aggregatable addressing

This paper proposes route advertisement policies (RAP) for the Border Gateway Protocol (BGP) with provider aggregatable (PA) addressing. The proposed RAP takes the advantage of address aggregation opportunity. If multiple address spaces are allocated to each of autonomous systems (ASes) that are multihomed to multiple upper ASes, reduction of the Forwarding Information Base (FIB) and quick convergence are achieved. However, multihoming based on PA addressing poses two limitations. One, more specific address information is hidden due to address aggregation. Two, multiple allocated address spaces per AS cause an address selection problem. To cope with these two limitations, we propose RAP to ensure connectivity among ASes with fewer routes installed in the FIB of each top layer AS. We implement the proposed RAP in an emulation environment with BGP (using the Quagga software suite) and our developed Hierarchical Automatic Number Allocation (HANA) protocols. We use HANA as a tool to automatically allocate hierarchical PA addresses to ASes. We confirm that with our proposed policies the FIB and RIB (Routing Information Base) sizes in top layer ASes do not change with the increase of stub ASes, and number of exchanged BGP update messages are reduced up to 67.3% than that of the case with conventional BGP RAP.