Eiichi Muramoto

Bandwidth Fair Application Layer Multicast for Multi-Party Video Conference Application

In this paper we propose bandwidth fair N-Tree algorithm for ALM distribution tree construction and a new protocol for ALM packet replication and distribution, namely Almcast. Both the tree construction algorithm and packet replication/distribution protocol were implemented as proof-of concept by modifying an existing multi-party video conference application. The results show that N-Tree algorithm takes less than 3ms to construct ALM distribution tree for 12 nodes. Almcast implementation enables the intermediate relay node to lookup for next destination, replicate and forward packets as fast as its receiving rate at application layer.

Treemap - The Fast Routing Convergence Method for Application Layer Multicast

Application Layer Multicast (ALM) is an alternative to overcome many problems that prevent IP multicast from widely using. However, when the overlay route changes, it takes time for end-hosts to update new routing table. In this paper, we propose Treemap-a technique to alleviate this problem. The main contribution of Treemap is to perform application layer routing which is self contained in a packet. As a result, end-hosts do not need to update new overlay route, yielding fast route adaptation when the overlay route changes. Furthermore, the Treemap technique can be used to extend Xcast6 (Explicit Multiunicast for IPv6). Xcast6 Treemap sends data in network layer multicast with the support of Xcast router, otherwise it works like ALM. With nominal packet header processing, Xcast6 Treemap is well suited for loss/time sensitive applications such as video conference.

NAT Free Open Source 3D Video Conferencing using SAMTK and Application Layer Router

SAMTK: Scalable Adaptive Multicast Toolkit is a toolkit to bridge the gap between network researchers and application developers in the field of multi-point communication. SAMTK includes a Qt based GUI that ensures a single source multi-platform use (Linux, FreeBSD, Windows and MacOS). It provides interfaces for network plugins used by one-to-many network sockets and a simple application programming interface for application developers to develop multi-point communication applications quite easily. ALR: Application Layer Router is a router which parses UDP packets and does a lookup in its internal forwarding table to duplicate and deliver the packets to multiple destinations. It provides NAT traversal function by using a singe UDP port both for session registration and packet delivery. The demo shows the feasibility of NAT free 3D video conferencing using Application Layer Router and the ease of development of video conferencing applications using SAMTK.

Functional and Performance Verification of Overlay Multicast Applications - A Product Level Approach

In this paper we present a testbed for the functional and performance verification and validation of product level overlay multicast (or ALM in short) applications which is a complex task due to humongous test patterns. Structured, systematic and simplified test environment is vital for product level quality validation. The key features of this testbed are network emulation, automated test scenario execution, log collection and testbed/real environment interconnectivity. The testbed uses StarBED as its mother testbed and netem as the network emulator. The key contributions of this work are calibration of netem in term of network emulation and establishing an architecture to use netem and StarBED for ALM system verification. The calibration of netem was carried out up to 30 pipes (logical links) and the results show the network emulation can be done at maximum 1.2% packet loss. One of the simple ALM verification experiments executed on the testbed took only 43 hours for execution completion compared to human execution which would take 15 weeks.

Demonstration of the Prototype of the Network Camera with Sender Initiated Congestion Control

We demonstrate the prototype of the network camera with a multicast transport-layer protocol called Sender Initiated Congestion Control (SICC) which provides adaptive flow control for multicast methods such as Application Layer Multicast (ALM) or eXplicit multi-unicast6 (XCAST6). SICC is capable of achieving fast congestion avoidance and significantly increases throughput at receivers while still remaining TCP friendly. We verified the applicability to small appliance by implementing SICC/XCAST6 on a prototype network camera We demonstrate the prototype of network camera and receiver terminals with viewer. It shows the capability of adaptive flow control to multiple receivers with or without competing traffics.

Design and Implementation of Sender Initiated Congestion Control

This paper reports the design and implementation of a multicast transport-layer protocol called Sender Initiated Congestion Control (SICC) which provides adaptive flow control for multicast methods such as Application Layer Multicast (ALM) or eXplicit multi-unicast (XCAST). SICC is a NAK based protocol and is designed to be extensible to adapt to various codecs, able to handle variable length of application data units (ADU) and to notify availability of ADU at the receiver for real-time streaming. We have implemented SICC in both user space on NetBSD and kernel space on Linux 2.6.10, and have used these implementations to evaluate TCP fairness. The results show the fairly shared bandwidth with 128 competing TCP flows with 1ms timer accuracy in various RTT. We also verified the applicability to small appliance by implementing SICC/XCAST6 on a prototype network camera and evaluated SICC in a field experiment.