多網家庭閘道器之設計與實作

Design and Implementation of a Multi-homing Home Gateway

趙丁漢(Ting-Han Chao)

指導教授 ： 蔡志宏

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.00199

摘要

隨著各種網際網路應用與服務的蓬勃發展，使用者的頻寬需求日益增大。雖然有許多寬頻接取技術(如ADSL與Cable Modem等)己被廣泛使用，但是單一網路介面的系統己經無法滿足這些使用者的頻寬需求。另一方面，許多無線寬頻接取技術(如WLAN與WiMAX等)己日漸成熟，加上相關產品與服務的價錢降低，多網系統(multi-homing devices)變得愈來愈受歡迎。
多網系統的主要目的為提升總接取頻寬與提高穩定度(reliability)。因此，負載平衡路由演算法是影響多網系統效能的一個重要因素。在本論文中，我們設計了一個使用IEEE 802.11g無線網路及ADSL線路作為接取網路的多網家庭閘道器，並且提出一個新穎的負載平衡路由演算法。此演算法將依網路狀況、網路應用的服務品質(QoS)要求以及不同網路上交通混合的效應來做路由決策。此外，我們採用IP tunneling技術達成seamless vertical handoff的功能。
我們在Linux平台上初步實作此多網家庭閘道器的系統雛型，並且與Linux Trunk System比較，以測試其效能。實驗結果顯示，本系統可達到的throughput遠高於Linux Trunk System，顯示本系統有較優越的頻寬使用效率。即使在高網路交通量的情況之下，本系統的throughput以及VoIP之語音品質仍然遠勝Linux Trunk System。我們也驗證了此系統的seamless vertical handoff能力。

關鍵字

多網接取 ； 服務品質 ； 交通混合 ； 負載平衡

並列摘要

Most users consistently have larger and larger bandwidth demand due to the rapid growth of applications and services over the Internet. Although there are various broadband access technologies such as ADSL and Cable modem, these heavy bandwidth users may not be satisfied with devices with a single network interface and its limited bandwidth. Together with the fact that various wireless broadband access technologies such as WLAN and WiMAX being mature, devices with multiple network interfaces (multi-homing devices) should become more and more popular.
The main purposes of multi-homing devices are to increase the total throughput, cost effectiveness as well as the reliability. Thus, the load balancing routing algorithm will be a definitive factor to the system performance. In this thesis, we design the architecture of a multi-homing home gateway with ADSL and IEEE 802.11g WLAN access networks, and propose a novel load balancing routing algorithm that takes the network status, QoS requirements of various applications, and traffic mixing effects on different networks into considerations. Moreover, we manipulate the IP tunneling technique to achieve the seamless handoff capability, when necessary.
In this study, we implement a prototype of the multi-homing home gateway in a Linux platform and test its performance. The throughput of the proposed system, called LoBRA System, is much higher than the Linux Trunk System, which is a popular Packet-based Inverse Multiplexing system implemented in Linux, indicating that the better bandwidth utilization can be achieved. Even under high traffic load, the LoBRA System still outperforms the Linux Trunk System in terms of throughput of FTP data transfers, or voice quality of VoIP applications. Finally, we also demonstrate the seamless handoff capability across different interfaces.

並列關鍵字

multi-homing ； QoS ； traffic mixing ； load balancing

參考文獻

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