US 5,781,726 A · Management of polling traffic in connection oriented protocol sessions

Abstract

Traffic involved in maintaining a set of connection oriented sessions between end stations in a network is managed to optimize and reduce the polling traffic needed to maintain the connection oriented sessions across a common link between edge devices. At a first edge device, a member of a set of connection oriented sessions is selected as a polling session. Request polling traffic of that polling session is forwarded from a first edge device to the second edge device. All other polling traffic from other members of the set of connection oriented sessions is blocked at the first edge device. The set of connection oriented sessions is maintained in response to polling traffic of the selected polling session. A similar algorithm is executed at the second edge device to manage the traffic in both directions across the common link. The step of selecting a polling session for use across the intermediate link includes changing the polling session from one to another member of the set of connection oriented sessions from time to time. Preferably, this is done in a round robin fashion, so that each of the connection oriented sessions is utilized in turn for maintaining the intermediate link. The technique is based on dividing the connection oriented sessions into a first link session between the first edge device and a first end station coupled to the first edge device, an immediate session between the first and second edge devices, and a second link session between the second edge device and a second end station coupled to the second edge device.

Claims36

Dependent claims

In a network including a plurality of end stations coupled to a first edge device, and at least one end station coupled to a second edge device, and in which the first edge device is coupled to the second edge device through a communication medium, a method for maintaining a set of connection oriented sessions between the plurality of end stations coupled to the first edge device and at least one end station coupled to the second edge device, each of the set of connection oriented sessions generating request and response polling traffic, the method comprising:

selecting, in the first edge device, a member of the set of connection oriented sessions as a polling session;
sending request polling traffic of the polling session from the first edge device to the second edge device and deferring request polling traffic of the other members of the set of connection oriented sessions received at the first edge device from the plurality of end stations;
and
maintaining the set of connection oriented sessions in response to response polling traffic of the polling session in the first edge device.

1 more element

in response to a time out of a session time out timer for a current connection oriented session in the first edge device, determining whether the current connection oriented session is a member of the set;
if the current connection oriented session is not a member of the set, then sending a request poll to the second edge device for the current connection oriented session and waiting for a timely response poll, and upon receipt of a timely response poll, resetting the session time out timer,
if the current connection oriented session is a member of the set, then selecting, in the first edge device, a member of the set of connection oriented sessions as a polling session;
and
if the current connection oriented session is selected, then sending a request poll from the first edge device to the second edge device and waiting for a timely response poll, and upon receipt of a timely response poll, resetting the session time out timer,
if the current connection oriented session is not selected, then resetting the session time out timer without sending a request poll.

3 more elements

dividing connection oriented sessions into a first link session between the first edge device and a first end station coupled to the first edge device, an intermediate link session between the first and second edge devices, and second link session between the second edge device and a second end station coupled to the second edge device;
responding to request polls received at the first edge device in the first link session by sending responses to the first end station;
responding to request polls received at the second edge device in the second link session by sending responses to the second end station;
and
maintaining session time out timers for respective connection oriented sessions in the first edge device;
in response to a time out of a session time out timer for a current connection oriented session in the first edge device, determining whether the current connection oriented session is a member of the set;
if the current connection oriented session is not a member of the set, then sending a request poll to the second edge device in the intermediate link session for the current connection oriented session and waiting for a timely response poll, and upon receipt of a timely response poll, resetting the session time out timer,
if the current connection oriented session is a member of the set, then selecting, in the first edge device, a member of the set of connection oriented sessions as a polling session;
and
if the current connection oriented session is selected, then sending a request poll from the first edge device to the second edge device and waiting for a timely response poll in the intermediate link session for the current connection oriented session, and upon receipt of a timely response poll, resetting the corresponding session time out timer,
if the current connection oriented session is not selected, then resetting the corresponding session time out timer without sending a request poll in the intermediate link session for the current connection oriented session.

8 more elements

Dependencies are inferred from the claim text.

Management of polling traffic in connection oriented protocol sessions

Life of this patent

Management of polling traffic in connection oriented protocol sessions

Life of this patent

Abstract

Claims36