Cisco Technology, Inc.

Andrew Joseph Mead

John Lautmann

Scott Allen Bales

Frank Gerard Bordonaro

Uwe Sellentin

Mark Denny

Scott Allan Bales

Arunkumar Bhushappagala Thippeswamy

A new directory service is established for a peer router receiving a data packet from an end station on a local area network connected to a port of the peer router, the peer router hereinafter being referred to as the source router. The data packet is addressed to a destination address. The source router determines that the data packet is to be encapsulated as an encapsulated packet, and the encapsulated packet routed by a peer-to-peer protocol to a destination router. The destination router then transmits the packet onto a local area network to the destination address. The source router locates the proper peer destination router by use of a database. The database is maintained on a server, where the database has entries for destination address, and an entry for a particular destination address gives the address of a peer router capable of routing a packet to that particular destination address. The database is populated by peer routers updating the database with information concerning the destination address which the peer routers can reach. The database on the server is interrogated by the source router to learn the address of a destination peer router, and an encapsulated packet is then transmitted onto a connectionless network for transmission to the destination router. The peer-to-peer routing protocol may be DLSw protocol. The database may be maintained in accordance with the X.500 directory standard. The database may be interrogated using the lightweight data access protocol (LDAP).

Directory services caching for network peer to peer service locator

A processor-based system configured for searching in dynamically balanced trees is configured for linking the most often-searched elements of the tree to optimize search performance. Data elements include pointers for a tree-based index ordering and a doubly-linked list based index ordering. A background process links the most often-searched elements according to the linked list ordering and maintains the linked list ordering by first determining those elements having the highest importance values, defined as a number of times an element is successfully searched relative to aging or decay function. The linked list ordering is then arranged based on descending importance values. Each element also includes a go-to-tree flag, indicating to a search engine the point at which it is no longer beneficial to continue searching according to the doubly-linked list ordering. Hence, a search engine that begins searching the elements according to the doubly-linked list ordering will begin searching of the tree structure for the specified key entry in response to detecting an element having a go-to-tree flag set to true. Hence, the doubly-linked list may optimize search performance when the most often-searched elements may be deep within a tree, while insuring that unnecessary overhead is not introduced into the search routine.

Arrangement for enhancing weighted element searches in dynamically balanced trees

A transparently-bridged wide area network connecting Ethernet/IEEE 802.3-based local area networks uses redundant proxy devices on each LAN for internetwork communications. The proxy devices on a given LAN, implemented as data link switching (DLSw) devices, identify amongst each other a master proxy device for mediating services to be provided to an end station on the local area network. Each proxy device connected to the local area network sends a request to the identified master proxy device in response to detecting a frame transmitted by an end station on the local area network, for permission to establish a circuit connection for transfer of the frame via a wide area network. The master proxy device, based on prescribed criteria, selects one of the proxy devices for transferring the frame, and sends a grant response to the selected proxy device. The master proxy device sends an 'inuse' response as a denial response to the other proxy devices indicating the corresponding request has been denied, thereby avoiding contention for proxy services. Databases within the proxy devices track the request, grants, and denials to minimize generation of repeated requests. The inventory of granted requests may also be modified based on failures detected within the master proxy device, or any proxy device having received grants. Hence, redundant DLSw-type proxy devices may be implemented on a local area network while maintaining a stable and a robust communications system.

Arrangement for controlling network proxy device traffic on a

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Durham, NC, United States of America

Andrew Joseph Mead