IMPROVING TRANSMISSION EFFICIENCY IN OPTICAL COMMUNICATION
- 1. IMPROVING TRANSMISSION EFFICIENCY IN OPTICAL COMMUNICATION Robert Radziwilowicz, Christian Charette Unlimi-Tech Software Inc., 205-1725 St. Laurent Blvd., Ottawa, ON, K1G 3V4 robertr@filecatalyst.com, ccharette@filecatalyst.com Abstract UDP is connectionless. It means that a datagram can be sent at any VI. Test results of the FileCatalyst UDP moment without prior advertising, negotiation or preparation. An application This work address problem of inefficient bandwidth utilization in optical program running over UDP must deal directly with end-to-end telecommunication systems that is caused by network impairments such as communication problems that a connection-oriented protocol would have latency, congestion, packet loss ratio and error ratio. handled. The proposed solution is software based system that implements User Java platform Datagram Protocol (UDP), Java platform. and custom designed transmission control mechanisms. Java is a programming language originally developed by Sun Microsystems (merged later into Oracle Corporation) and released in 1995 as a core component of Sun Microsystems' Java platform. I. Problem Every year there is observed increase in amount of data that is transmitted over the public telecommunication infrastructure. The predicted future growth in data transfer (figure 1) creates challenges for 10Mb/s available bandwidth network operators and service providers. Communication systems will have to accommodate growing demand for bandwidth within justifiable budget limits. Java offers versatile, efficient, portable, secure and platform independent technology for developing network computing and communication systems. IV. Implementation Sender Multi-thread Output List of Output buffers scheduler sockets blocks reading HDD Transmitter TRUNK E/O Files to be Fragmentation transmitted into packets Receiver Input Multi-thread Assembling 100Mb/s available bandwidth Input buffers packet blocks Send negative sockets processor NO ACK to client Receiver YES writing TRUNK O/E Figure1 Predictions about data transmission over the Internet. Is block complete? HDD Optical communication is the technology of choice for large data transfer over long distances. Although optical fiber does offer nearly unlimited Transmission control bandwidth, technologies that are used for data transmitting and receiving sender Congestion control receiver have limited capability of dealing with network impairments such as latency, FTP and FTP congestion, packet loss ratio and error ratio. The traditional model of data Error check transmission requires TCP to TCP TCP perform transmission control. Network impairments leads to ineffective utilization of the available IP IP bandwidth and this increases overall costs of network maintenance. ..... Internet ..... The improvement in use of the available bandwidth can be introduced in two The FileCatalyst system ways: performs transmission sender receiver control in the user Congestion control 1Gb/s available bandwidth ● Modification of the physical infrastructure This method involves upgrading transmission hardware and deploying application layer. and Error check new optical fibres. It is time consuming, expensive to implement and it This model allows offers requires long term logistic planing. significant flexibility in UDP UDP adjusting to customer IP IP ● Modifications of the network application layer network architecture and ..... Internet ..... This method involves modifications in client-server application topology. software. It is platform independent and it does not require changes in physical network infrastructure. Data rate control Sender RTT Receiver Sender packets Receiver II. Proposed solution RTT is spiking NACK is spiking Slow down Slow down Research team at the Unlimi-Tech Software Inc. developed the FileCatalyst system that supports 10G optical telecommunication infrastructure. V. Performance evaluation setup The offered solution significantly improves bandwidth utilization in multi- gigabit optical transmission systems and it does not require any The optical communication link was built to perform benchmark tests and to 10Gb/s available bandwidth modifications in existing telecommunication infrastructure. evaluate performance of the system in different network environments. The Netropy 10G was used to introduce controlled packet loss and latency to the VII. Conclusions FileCatalyst system incorporates cost efficient technologies such as User transmission link. Combination of UDP, Java and custom technologies for transmission control, offers Datagram Protocol (UDP) and Java platform and it offers complete solution flexible and cost efficient platform that significantly improve utilization of the available that can be integrated with existing IT and communication systems. 10m 10m bandwidth. 1550nm SMF 1550nm SMF FileCatalyst has following features: ● Does not need modifications of the hardware layer in telecommunication infrastructure III. Technologies implemented Server ● Provides support for 10G (and beyond) infrastructure Client: Apposite Netropy 10G ● Intel Xeon (2 processor, 12 ● It is platform independent with low CAPEX and low OPEX ● AMD Opteron (2 processor, 16 Variables: cores HT, 3.4GHz) User Datagram Protocol cores, 2.4GHz) ● latency ● OS: Ubuntu 10.04.1 ● OS: Ubuntu 11.04 ● packet loss User Datagram Protocol (UDP) is a connectionless protocol that, like TCP, ● Drive: 24GB RAM Drive ● Drive: 2 x Adaptec RAID controller, 8 x SSD drives, VIII. Successful deployments ● TCP: Standard Linux FTP runs on top of IP networks. It allows network hosts to send messages RAID 0 for performance. client ● TCP: Pure-FTPD v1.0.24-1 (datagrams) to other hosts across the network without requiring to set up ● UDP: FileCatalyst CLI v3.0 ● UDP: FileCatalyst v3.0 special transmission channels or data paths. The benchmark tests were performed for different values of available The UDP in its basic form, that is defined in standard STD-6/RFC-768, does bandwidth, latency and packet loss ratio. The effective data rate was not have any mechanisms for fragmentation and reassembly, flow control measured when data was transmitted with standard FTP/TCP and with and congestion avoidance. FileCatalyst system.