Research On Interdomain Routing Based On Multiple Available Paths

With the development of network technology, the number of Internet users increased greatly. Moreover, new applications challenge the performance of Internet further. Toward new trend and requirement of Internet, 973 major research project "Trusted Network and Pervasive integration service system " was started to break the limitation of today's Internet and tried to resolve the problems in scalability, reliability of routing systems by novel generalized routing and switching theories.To solve these problems, this thesis introduces a novel multipath inter-domain proposal to tackle with the problems in routing reliability and the efficiency of network resource. Specifically, the contributions of this thesis are as these follows:1. To construct a scalable routing architecture, this thesis introduces a novel routing architecture, which named"Multipath inter-domain Routing Based on Independent Addresses (MRBIA)". MRBIA decouples the locator/ID information of terminals, and adopts different addressing space to mark inter-domain routing identifiers and intra-domain routing identifiers. Simulation results indicate that the number of route entries in MRBIA could be satisfied with the hardware's demand in conservative conditions. Moreover, MRBIA could achieve interconnectivity of heterogeneous stub networks and offer good scalability for inter-domain routing systems.2. To answer the question whether introducing multipath inter-domain routing could acquire more profits in operation scope, this thesis adopts a new analysis method to compare the profits of ISP between single path routing manner and multipath inter-domain routing manner based on economic factors. The theoretical analysis and simulation results indicate that it is very difficult for single path routing to balance ISP profits and user satisfactory. On the contrary, the multipath inter-domain routing could offer more bandwidth to be deployed so that ISP could achieve more profits and users could acquire better service performance at the same time. So, the research on multipath inter-domain routing has not only theoretical benefits but also practical significance.3. An inter-domain routing announcement method based on Valley-free constraints was proposed. Compared with the current routing announcement method, this proposal keeps the complex strategies and private information protection but involves special information to indicate whether this announcement traversed a P-C path or P-P path. In this way, wrong routing announcement, which would result in the imbalance of traffic distribution, the instability of networks, caused by router fault or administrator's misconfiguration could be avoided effectively. So, this mechanism could offer correctness guarantee for multipath acquiring process.4. This thesis proves the loop-freeness condition for inter-domain routing based on multiple available paths and offers a method based on the collaborative operation of control and data plane. Furthermore, a novel method for fuzzy multipath selection is offered. The theoretical analysis shows that the complexity of multiple available paths selection algorithm is O (N) which could satisfy with the scalability of router calculation cost. The simulation results indicate that the inter-connectivity ratio between ASes could achieve 95% by our proposal. In addition, the number of available routes, which will be selected by fuzzy multipath selection method, could be increased 20% than equal cost multipath routing method to offer more space for multipath selection.5. Based on the proposal of fuzzy multipath inter-domain routing method, this thesis gives some advises in how to use multipath concurrently based on the economic accounting relationships, the tangible costs and the intangible costs. Then, a traffic switching mechanism is given by links cost-effective ratio optimization model. The theoretical analyses indicate that the none-account relationship might not better than mutual-account relationship in some traffic distribution conditions. In addition, according to the comparison result of optimal path forwarding manner and multipath traffic diversion plan, this thesis finds that the average cost-effective ratio will be increased 10.23% and the peak ratio could improve 105% by our proposal, which will prove the efficiency of traffic diversion plan further.