Lucent Technologies Inc.

Alcatel Lucent

At&t Bell Laboratories

At&t Company

On-Ching Yue

Mooi Choo Chuah

Qinqing Zhang

Bharat Tarachand Doshi

Anlu Yan

Ashwin Sampath

Yung-Terng Wang

Kazem Anaraky Sohraby

Kotikalapudi Sriram

Enrique Hernandez-Valencia

Kai Y Eng

Wing Cheong Lau

Kirk K Chang

Hongbin Ji

Daniel R Jeske

Yuval V Lirov

Tzyh-Jong Wang

Eraj D Kaluarachchi

Wolfgang Fleischer

Muralidhran S Kodialam

Swaminathan Ravikumar

Tim Ozugur

The present invention provides systems and methods for providing distributed, adaptive IP filtering techniques used in detecting and blocking IP packets involved in DDOS attacks through the use of Bloom Filters and leaky-bucket concepts to identify 'attack' flows. In an exemplary embodiment of the present invention, a device tracks certain criteria of all IP packets traveling from IP sources outside a security perimeter to network devices within the security perimeter. The present invention examines the criteria and places them in different classifications in a uniformly random manner, estimates the amount of criteria normally received and then determines when a group of stored classifications is too excessive to be considered normal for a given period of time. After the device determines the criteria that excessive IP packets have in common, the device then determines rules to identify the packets that meet such criteria and filters or blocks so identified packets.

Methods and devices for providing distributed, adaptive IP filtering against distributed denial of service attacks

A method and apparatus are disclosed for measuring the usage of a communications network, based on a two level sampling and measuring technique. A sampling interval, T, represents the intervals at which the network resource is observed. In addition, during each sampling interval, a measurement window of length, &#x3c4;, is utilized. Generally, while the values for the sampling interval, T, and the measurement window, &#x3c4;, are calibrated, actual measurements are only taken for the smaller measurement window, &#x3c4;, and the actual measurements are extrapolated to estimate the usage over the larger sampling interval, T. The sampling interval, T, and measurement window, &#x3c4;, values may be periodically recalibrated. An extrapolation process consists of two phases: (i) a 'learning period' (LP) during which both exact and extrapolated measurements are performed, the error is determined, and, if necessary, adjustments are made to the values of the sampling interval, T, and the measurement window, &#x3c4;; and (ii) a 'measurement and extrapolation period' (MEP) during which only measurements during the sampling interval, T, continue and the sampled measurements are extrapolated without performing the exact measurements. Several learning periods, LPs, may be interleaved during a communication session with larger measurement and extrapolation period, MEP, intervals.

Resource usage measurement technique for pricing in a communications network

Call admission methods for admitting connections into ATM/IP networks having a plurality of communication channels are disclosed. An overbooking technique is utilized which distinguishes among the different service classes. Each service class is assigned an overbooking factor. The call admission is determined based on the overbooking factor assigned to the class and the effective bandwidth for that service class. In addition, methods are disclosed for performing appropriate bookkeeping, i.e., updating and maintaining information concerning the state of the system.

Call admission control with overbooking support and cell loss ratio and cell delay variation guarantee

Methods and systems are provided for improving frame selection in wireless communications networks. During decoding of a frame, a base station generates an error burst representation associated with error bursts and stores the representation within the frame, thus forming an enhanced frame. The base station then transfers the enhanced frame to a network controller. A frame selection unit ('FSU') within the network controller thereafter applies frame selection to the enhanced frame. The error burst representation can be analyzed to determine the quality of the enhanced frame. A 'combined' frame, generated by combining an &#x201c;acceptable&#x201d; portion of the enhanced frame and an acceptable portion of a copy of the enhanced frame, can then be generated to substantially eliminate errors. The present frame selection methods and systems enable superior quality frames to be passed on to higher layers in a network's communications protocol (hereafter collectively referred to as &#x201c;network&#x201d;).

Methods and systems for improving frame selection in wireless communications networks

A new algorithm for clock offset estimation for resources distributed across a network (such as the Internet). By exchanging a sequence of time-stamped messages between pairs of network nodes and separately estimating variable delays for each message direction, present inventive embodiments provide estimates for clock offset between node pairs and the bias of such estimates, thereby to permit more accurate correction. Present inventive algorithms operate in a variety of peer and server network configurations while providing significant improvement in convergence speed and accuracy.

Clock offset estimation with bias correction

A packet encapsulation scheme for multiplexing application sessions&#x2014;Lightweight IP Encapsulation (LIPE)&#x2014;is described. An LIPE packet comprises at least one multiplexing header (NH) and associated multimedia data packet (MDP). The LIPE packet uses UDP/IP as transport. An MH field further comprises a 16-bit a user identifier (UID) field, an 11 bit length indicator (LNG) field, a 1 bit 'more' (M) field and an optional payload type/class of service (PT/CoS) field comprising 8 bits.

Lightweight internet protocol encapsulation (LIPE) scheme for multimedia traffic transport

The present invention provides an improved RACH access burst arrangement and frame structure. That is, the invention provides methods and apparatus for supporting more than one access burst length in the UMTS access channel structure. Preferably, two access burst lengths are supported, e.g., 5 ms and 10 ms. Such an arrangement is advantageous in applications where it is beneficial to have fast access latency such as, for example, voice or other forms of real-time traffic. Also, the invention provides methods and apparatus for supporting multiple frame sizes. It is to be appreciated that further enhancement to access latency can be obtained by having the UMTS physical layer support multiple frame sizes. The access burst signal transmitted by a remote terminal over the RACH may be an access request or data packets in the case where the RACH is being utilized for UMTS short message services.

Methods and apparatus for providing short RACH frames for fast latency

Overhead is reduced and packet transport efficiency is increased for a flow of switched packets from a router by identifying a plurality of packets having a common destination node within a network and transmitting at least one control message to establish the flow of switched packets; the at least one control message including: (i) a label mapping message corresponding to the flow of switched packets and (ii) a header removal field. Packet headers corresponding to packets of a switched packet flow are not parsed, therefore either the entire header, or a portion of the header, may be removed from each packet assigned a label. A header removal field is shared among routers while signaling to establish a labeled flow. The header removal field is used to provide header structure information to those routers which will be utilized for transport of the subsequent labeled flow. Thus, since layer two switching utilizes the appended label instead of the packet header for conveying a labeled packet, the packet header may be partially or completely removed. The header removal field is used to inform routers utilized for a labeled packet flow which portions of the subsequently conveyed packet headers will be removed and which portions will be present.

Packet transport method device utilizing header removal fields

An Internet Protocol (IP)-based network incorporates an application level switching server and a number of packet endpoints. A packet endpoint multiplexes application sessions destined for different packet endpoints into one multiplexed session that is terminated with the application level switching server. The latter extracts each application session (or packets associated therewith) and repackages, or switches, them into other multiplexed sessions such that at least two switched packets are transmitted to different packet endpoints. The multiplexed sessions utilize either RTP/UDP/IP or UDP/IP encapsulation.

Application-level switching server for internet protocol (IP) based networks

A Universal Mobile Telecommunications System (&ldquo;UMTS&rdquo;) is modified to provide location-determining services similar to Wireless-Assisted-GPS (&ldquo;WAG&rdquo;) services to mobiles without requiring the deployment of a GPS receiver inside the UMTS network. The resulting network is known as a UMTS Network Assisted GPS (&ldquo;UNAG&rdquo;) network. A UNAG network is created by deploying a UNAG server inside a UMTS network. The UNAG server provides WAG-like services to mobiles. Only one UNAG server is needed in an entire system, allowing the cost of the UNAG server to be amortized over a number of Mobile Switching Centers (&ldquo;MSCs&rdquo;) in the UMTS network. The UNAG server provides excellent location-prediction accuracy and reduces the amount of time required to determine the location of a mobile in a UMTS network.

Methods and systems for determining the location of mobiles in a UMTS telecommunications system

In a Universal Mobile Telecommunications System (UMTS) based wireless system, a channelization code-tree is partitioned into two sets: a permanent set and shared a shared set. Those codes in the permanent set are assigned to low data rate users for the duration of a session, or connection. Those codes in the shared set are assigned to high data rate users on a frame-by-frame basis using a downlink shared (DSCH) channel. The partition boundary between the permanent set and the shared set can be dynamically shifted based on traffic conditions.

Dynamic code allocation for downlink shared channels

The present invention provides methods and apparatus for providing access priority in a MAC protocol of a communications system such as, for example, with respect to UMTS RACH. Particularly, the invention introduces several access priority methodologies including: (i) random chip delay access priority (RCDAP); (ii) random backoff based access priority (RBBAP); (iii) variable logical channel based access priority (VLCAP); (iv) UMTS-specific variable logical channel based access priority (VLCAP&prime;); (v) probability based access priority (PBAP); and (vi) retransmission based access priority (REBAP). Each methodology associates some parameter or parameters to access priority classes in order to influence the likelihood of a remote terminal completing a successful access request to a base station.

Methods and apparatus for random chip delay access priority in a communications system

The specification relates to a device and method utilized for packaging voice data (and other delay critical 'connection' or 'flow' type application data) for point-to-point transport from one Packet Circuit Gateway (PCG) to a second PCG over Label Switching Routers (LSRs) within an Internet Protocol (IP) network; the beneficial aspects of the packaging format being: (i) a reduced overhead requirement when compared to conventional IP telephony due to inclusion of a switching label in lieu of an appended IP header, thereby increasing network bandwidth efficiency, and (ii) the increased transport speed associated with layer two label switching when compared to layer three forwarding.

Point-to-point data transport over the internet utilizing label switching without IP headers

Methods and apparatus for random backoff based access priority in a communications system

The present invention provides a method for use in a UMTS receiver of detecting a signal transmitted by a UMTS transmitter which includes determining whether the signal is greater than or equal to at least a first power threshold value when the signal is below an initial detection threshold value, and informing the transmitter when the signal is greater than or equal to the first power threshold value such that the transmitter can increase a signal strength of the signal by a first predetermined amount and re-transmit. In another aspect of the invention, a method for use in a UMTS transmitter of power ramping a signal transmitted by the transmitter and received by a UMTS receiver includes increasing a signal strength of the signal by a first predetermined amount when informed by the receiver that the signal is greater than or equal to a first power threshold value but below an initial detection threshold value, and re-transmitting the signal.

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Middletown, NJ, United States of America

On-Ching Yue