TOPS: an architecture for telephony over packet networks

Abstract

Abstract-Packet telephony is of increasing interest in both the telecommunications and internet communities. The emergence of packet telephony will create new services, and presents an opportunity to rethink how conventional telephony services are implemented. In this paper, we present an architecture for telephony over packet networks (TOPS). TOPS allows users to move between terminals or to use mobile terminals while being reachable by the same name. TOPS users can have multiple terminals and control how calls are routed to them. TOPS allows for terminals with a range of capabilities such as support for video, whiteboard, and other media with a variety of coding formats. TOPS retains the necessary information on terminal capabilities to determine the appropriate type of communication to be established with the remote terminal. The architecture assumes that the underlying network supports the establishment of end-toend connectivity between terminals, with an appropriate quality of service.The components of TOPS are a directory service, an application layer signaling protocol, and a logical channel abstraction for communication between end-systems. The directory service maps a user's name to a set of terminals where the user may be reached. A user can control the translation operation by specifying profiles that customize how his name is mapped to a set of terminals where he can be reached. Terminal capabilities are also stored in the directory service. The application layer signaling protocol establishes and maintains call state between communicating terminals. The logical channel abstraction provides a shared endto-end context for a call's constituent media and control streams, while isolating the applications from the details of the network transport mechanisms. In addition to supporting simple pointto-point calls, the architecture supports both centralized and decentralized conferencing. We also introduce a simple encapsulation format for voice.

Host Mobility Using an Internet Indirection Infrastructure

“…In contrast, personal and session mobility schemes (e.g., The Mobile People Architecture (MPA) [16] ICEBERG [30], and Telephony Over Packet networkS [1]) track people or sessions. This allows redirection of new sessions or migration of active sessions to a completely different application or device according to user connectivity (e.g., which devices are currently accessible to the user) and user preferences (e.g., less expensive or higher performance).…”

“…Chord assumes a cir- 1 In the implementation presented in this paper, we use Ñ ¾ . Such a large value of Ñ allows end hosts to choose trigger identifiers independently since the chance of collision is minimal.…”

“…Personal/session mobility allows a user to redirect a new session or migrate an active one from one application or device to another when a better choice becomes available [1] [16] [30]. Applications or devices may fail (e.g., a cell phone may have poor coverage indoors) or a better performance/price option may become available (e.g., video conferencing on a laptop connected to a free 11Mb/s 802.11b network is preferable to a cell phone connected to a 128Kb/s GPRS network).…”

ICEBERG: an Internet core network architecture for integrated communications

“…TOPS [3] is a packet telephony architecture which includes a directory service, application layer signaling protocol, a logical channel abstraction, and an encapsulation format to insulate telephony applications from the underlying network transport capabilities, and mechanisms to support a variety of conferencing modes. The directory service is the key component of the system.…”

Global roaming and personal mobility with COPS architecture in SuperDHLR

“…The concept of personal mobility has been introduced [3,5,8,10,12], allowing a user to move from one terminal to another while receiving the same service. Some of the proposed approaches, however, assume mobility in the same type of network [5], and others rely on the introduction of a new protocol suite for realizing personal mobility [3,10]. Furthermore, most proposals realize personal mobility by mapping a personal address to a terminal address in a way that requires an additional home location register (HLR) interrogation to map it to the roaming location.…”