At+t Corp.

At&t Bell Laboratories

Arthur W Berger

Ward Whitt

Rodolfo Alberto Milito

Yaakov Kogan

When a network element receives a request for an increase in bandwidth via a resource management (RM) cell, the network element determines the rate that it can support. If the rate that the network element can support is less than the requested rate, rather than simply rejecting the requested rate, the network element overwrites the rate encoded in the appropriate field in the arriving RM cell with a lower rate than requested. If the network element can support the requested rate, the rate encoded in the RM cell is left unchanged and the RM cell is transmitted to the network along the connection.

Flexible bandwidth negotiation for the block transfer of data

A method for dimensioning link bandwidth for elastic-data traffic for a link in a communications network, in which a number of connections N having elastic-data traffic flowing over a bottlenecked link in a communications network is determined. A transfer rate &quest;f for each connection is determined for the condition that the communications network is not a constraining resource for the connection. A per-connection bandwidth objective b is determined for elastic-data traffic flowing over the link. Lastly, a link bandwidth B for the link is dimensioned for the elastic-data traffic flowing over the link based on either a mean performance criterion or a tail performance criterion using the determined number of connections N, the determined transfer rate for each connection and the determined per-connection bandwidth objective b.

Dimensioning bandwidth and connection admission control for elastic traffic in high-speed communication networks

A method is provided for admitting new requests for service in a shared resource having a capacity. The new request has service priority levels associated therewith. In one embodiment of the invention, for example, the shared resource may be a packet communications network and the service request may be a request to admit a new connection. The method proceeds as follows. First, for each service priority level on said shared resource, a total effective bandwidth is generated which is represented by a sum of individual effective bandwidths of previously admitted requests for service. Subsequent to receiving a new request for service having a specified priority of service level, a plurality of effective bandwidths are accessed for the new request. The plurality of effective bandwidths are respectively associated with the specified service priority level and service priority levels therebelow. The new request is admitted if, for the specified service priority level and for each service priority level therebelow, the sum of (i) said total effective bandwidth for a given service priority level and (ii) for said new request, the effective bandwidth at the given service priority is less than the capacity.

Traffic management in packet communication networks having service

A fair and efficient admission scheme enables sharing of a common resource among N traffic classes, such that each class is guaranteed (on a suitable long-term basis) a contracted minimum use of the resource, and each class can go beyond the contract when extra resource capacity becomes temporarily available. The scheme operates in an open loop mode, and thus does not require information describing the current status of the resource. For the purposes of description, one form of the invention is best described in terms of 'tokens' and 'token banks' with finite sizes. Our scheme uses one token bank per class (bank `i`, i= 1, . . . ,N), plus one spare bank. Class `i` is preassigned a rate, rate(i), i=1, . . . ,N, that represents the 'guaranteed throughput' or contracted admission rate for class `i`. Tokens are sent to bank `i` at rate(i). Tokens that find a full bank are sent to the spare bank. When the spare bank is also full, the token is lost. Every admitted arrival consumes a token. A class `i` arrival looks first for a token at bank `i`. If bank `i` is empty, it looks for a token at the spare bank. If the latter is also empty, the arrival is blocked.

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Fair Haven, NJ, United States of America

Arthur W Berger