Communication apparatus and methods

• US 5,610,905 A
• Filed: 12/13/1994
• Issued: 03/11/1997
• Est. Priority Date: 07/19/1993
• Status: Expired due to Term

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Alantec Corp. (Cornhill Corp. Holdings LLP)
• Inventors: Wakerly, John E., Laursen, Arthur I., Murthy, Manohar
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): VU, HUY DUY
• Application Number:
  US08/358,211
• Time in Patent Office: 819 Days
• Field of Search: 370/85.13, 370/85.14, 370/85.15, 370/13, 370/17, 370/60, 370/61, 370/68.1, 370/94.1, 370/110.1, 340/825.06, 340/825.07
• US Class Current: 370/401
• CPC Class Codes: H04L 12/46 Interconnection of networks
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks

Abstract

A multi-port packet-based bridge is described in which packet transmissions on particular ports or between ports may be monitored on another, monitoring port. Efficient operation is realized by using a multi-processor environment and data structures that allow a packet received on one port to be transmitted to multiple ports without being "copied" multiple times. By using a Supervisory Access Terminal, it is possible to specify various circumstances under which a packet will be sent to the monitoring port. These circumstances include monitoring of all packets incoming to a selected port (or ports), all packets forwarded to a selected port (or ports), and packets generated internally and sent to a selected port (or ports). In addition, all packets forwarded from one selected port to another selected port may be monitored. Port monitoring is supported by particular data structures that promote efficient dispatching of packets and by a Bridging Cache that retains the results of recent dispatch calculations. Similar techniques are applied to multi-port routers.

Claims

1. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more network segments each of which is accessible to a network monitor; and

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,

wherein the first means comprises means for transmitting each of one or more packets;

(1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus; and

, in addition, (2) to one or more monitoring ports, wherein each monitoring port is one of the plurality of ports and wherein each monitoring port allows connection to a network segment accessible to a network monitor.

2. The apparatus of claim 1 further comprising means for designating any one of the plurality of ports as a monitoring port.

3. The apparatus of claim 1 wherein each of the plurality of ports allows connection to a network segment.

4. The apparatus of claim 3 wherein the plurality of ports comprises:

one or more ports for connection to one or more network segments employing a first protocol format; and

one or more ports for connection to one or more network segments employing a second protocol format different from the first protocol format;

wherein the one or more monitoring ports include a first monitoring port for connection to a network segment employing the first protocol format; and

wherein the first means comprises means to translate packets from the second protocol format to the first protocol format to allow packets received from a network segment employing the second protocol format to be transmitted to the first monitoring port.

5. The apparatus of claim 1 wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted;

and

wherein the apparatus further comprises second means to modify the data structures in response to commands so as to define which packets should be transmitted to which monitoring ports.

6. The apparatus of claim 5 further comprising a supervisory terminal for entering the commands and providing them to the second means.

7. The apparatus of claim 5 wherein the commands include a command to transmit to a monitoring port packets incoming on a selected port.

8. The apparatus of claim 5 wherein the commands include a command to transmit to a monitoring port packets forwarded to a selected port for transmission.

9. The apparatus of claim 5 further comprising means for generating packets,

wherein the commands include a command to transmit to a monitoring port packets generated by the means for generating packets.

10. The apparatus of claim 5 further comprising means for generating packets,

wherein the commands include a command to transmit to a monitoring port packets that are generated by the means for generating packets and forwarded to a selected port for transmission.

11. The apparatus of claim 5 wherein the commands include a command to transmit to a monitoring port packets incoming on a first selected port and forwarded to a second selected port for transmission.

12. The apparatus of claim 5 wherein the commands include a command to restore the data structures to their state existing before an application of any command to transmit any packet to any monitoring port.

13. The apparatus of claim 1 wherein the first means comprises means for applying one or more custom filtering rules to determine which packets are to be transmitted to a monitoring port.

14. The apparatus of claim 1 wherein the packets have a variable number of data units.

15. The apparatus of claim 1, wherein the first means allows transmitting a packet at substantially the same time:

(1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports.

29. The apparatus of claim 1 further comprising

second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports.

30. The apparatus of claim 29 wherein the second means is invocable repeatedly to change a specification of packets during the operation of the first means.

44. The apparatus of claim 29 wherein the packets have a variable number of data units.

one or more of the plurality of network segments employ a second protocol format different from the first protocol format;

at least one network segment comprising a network monitor employs the first protocol format; and

said method further comprises translating one or more packets received on one or more network segments employing the second protocol format from the second protocol format to the first protocol format and transmitting such packets to a network segment which comprises a network monitor and employs the first protocol format.

46. The method of claim 15 further comprising entering the command from a supervisory terminal connected to the apparatus.

47. The method of claim 15 wherein the command is a command to transmit to a network segment comprising a network monitor packets incoming from a selected network segment.

48. The method of claim 15 wherein the command is a command to transmit to a network segment comprising a network monitor packets transmitted in step (b) to a selected network segment.

16. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems; and

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,

wherein the first means allows transmitting a packet at substantially the same time;

(1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

the apparatus further comprising means for designating any one of the plurality of ports as a monitoring port.

19. The apparatus of claim 16 wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted;

and

wherein the apparatus further comprises second means to modify the data structures in response to commands so as to define which packets should be transmitted to which monitoring ports.

20. The apparatus of claim 19 further comprising a supervisory terminal for entering the commands and providing them to the second means.

23. The apparatus of claim 19 further comprising means for generating packets,

wherein the commands include a command to transmit to a monitoring port packets generated by the means for generating packets.

24. The apparatus of claim 19 further comprising means for generating packets,

wherein the commands include a command to transmit to a monitoring port packets that are generated by the means for generating packets and forwarded to a selected port for transmission.

28. The apparatus of claim 16 wherein the packets have a variable number of data units.

17. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems; and

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,

wherein the first means allows transmitting a packet at substantially the same time;

(1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system, and

wherein each of the plurality of ports allows connection to a network segment.

18. The apparatus of claim 17 wherein the plurality of ports comprises:

one or more ports for connection to one or more network segments employing a first protocol format; and

one or more ports for connection to one or more network segments employing a second protocol format different from the first protocol format;

wherein the one or more monitoring ports include a first monitoring port for connection to a network segment employing the first protocol format; and

wherein the first means comprises means to translate packets from the second protocol format to the first protocol format to allow packets received from a network segment employing the second protocol format to be transmitted to the first monitoring port.

21. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems; and

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,

wherein the first means allows transmitting a packet at substantially the same time;

(1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted,

wherein the apparatus further comprises second means to modify the data structures in response to commands so as to define which packets should be transmitted to which monitoring ports, and

wherein the commands include a command to transmit to a monitoring port packets incoming on a selected port.

22. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems; and

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,

wherein the first means allows transmitting a packet at substantially the same time;

(1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted;

wherein the apparatus further comprises second means to modify the data structures in response to commands so as to define which packets should be transmitted to which monitoring ports, and

wherein the commands include a command to transmit to a monitoring port packets forwarded to a selected port for transmission.

25. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems; and

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,

wherein the first means allows transmitting a packet at substantially the same time;

(1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted,

wherein the apparatus further comprises second means to modify the data structures in response to commands so as to define which packets should be transmitted to which monitoring ports, and

wherein the commands include a command to transmit to a monitoring port packets incoming on a first selected port and forwarded to a second selected port for transmission.

26. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems; and

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,

wherein the first means allows transmitting a packet at substantially the same time;

(1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted,

wherein the apparatus further comprises second means to modify the data structures in response to commands so as to define which packets should be transmitted to which monitoring ports, and

wherein the commands include a command to restore the data structures to their state existing before an application of any command to transmit any packet to any monitoring port.

27. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems; and

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,

wherein the first means allows transmitting a packet at substantially the same time;

(1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system, and

wherein the first means comprises means for applying one or more custom filtering rules to determine which packets are to be transmitted to a monitoring port.

31. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems;

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination; and

second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises means for transmitting each specified packet;

(1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus; and

, in addition, (2) to one or more monitoring ports, and

wherein the second means comprises means for designating any one of the plurality of ports as a monitoring port.

32. The apparatus of claim 31 wherein the second means is invocable repeatedly to change a specification of packets, and designate any one of the plurality of ports as a monitoring port, during the operation of the first means.

35. The apparatus of claim 31 wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted, and

wherein the second means comprises means to modify the data structures in response to commands so as to specify to the first means which packets should be transmitted to which monitoring ports.

36. The apparatus of claim 35 further comprising a supervisory terminal for entering the commands and providing them to the modifying means.

39. The apparatus of claim 35 further comprising means for generating packets,

wherein the commands include a command to transmit to a monitoring port packets generated by the means for generating packets.

40. The apparatus of claim 35 further comprising means for generating packets,

wherein the commands include a command to transmit to a monitoring port packets that are generated by the means for generating packets and forwarded to a selected port for transmission.

33. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems;

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination; and

second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises means for transmitting each specified packet;

(1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus; and

, in addition, (2) to one or more monitoring ports, and

wherein each of the plurality of ports allows connection to a network segment.

34. The apparatus of claim 33 wherein the plurality of ports comprises:

one or more ports for connection to one or more network segments employing a first protocol format; and

one or more ports for connection to one or more network segments employing a second protocol format different from the first protocol format;

wherein the one or more monitoring ports include a first monitoring port for connection to a network segment employing the first protocol format; and

wherein the first means comprises means to translate packets from the second protocol format to the first protocol format to allow packets received from a network segment employing the second protocol format to be transmitted to the first monitoring port.

37. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems;

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination; and

second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises means for transmitting each specified packet;

(1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus; and

, in addition, (2) to one or more monitoring ports,

wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted,

wherein the second means comprises means to modify the data structures in response to commands so as to specify to the first means which packets should be transmitted to which monitoring ports, and

wherein the commands include a command to transmit to a monitoring port packets incoming on a selected port.

38. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems;

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination; and

second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises means for transmitting each specified packet;

(1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus; and

, in addition, (2) to one or more monitoring ports,

wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted,

wherein the second means comprises means to modify the data structures in response to commands so as to specify to the first means which packets should be transmitted to which monitoring ports, and

wherein the commands include a command to transmit to a monitoring port packets forwarded to a selected port for transmission.

41. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems;

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination; and

second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises means for transmitting each specified packet;

(1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus; and

, in addition, (2) to one or more monitoring ports,

wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted,

wherein the second means comprises means to modify the data structures in response to commands so as to specify to the first means which packets should be transmitted to which monitoring ports, and

wherein the commands include a command to transmit to a monitoring port packets incoming on a first selected port and forwarded to a second selected port for transmission.

42. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems;

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination; and

second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises means for transmitting each specified packet;

(1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus; and

, in addition, (2) to one or more monitoring ports,

wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet'"'"'s forwarding information, all the ports, if any, to which the packet is to be transmitted,

wherein the second means comprises means to modify the data structures in response to commands so as to specify to the first means which packets should be transmitted to which monitoring ports, and

wherein the commands include a command to restore the data structures to their state existing before an application of any command to transmit any packet to any monitoring port.

43. An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

a plurality of ports for connection to the units and to one or more monitoring systems;

first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination; and

second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,

wherein the first means comprises means for transmitting each specified packet;

(1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus; and

, in addition, (2) to one or more monitoring ports, and

wherein the first means comprises means for applying one or more custom filtering rules to determine which packets are to be transmitted to a monitoring port.

45. A method for monitoring a network comprising an apparatus interconnecting a plurality of network segments at least one of which comprises a network monitor, the method comprising:

(a) obtaining, from each packet received by the apparatus, forwarding information to be used in determining the packet destination;

(b) if a packet destination includes a station other than the apparatus, then transmitting the packet to one or more of the network segments in order to deliver the packet to the packet destination;

(c) if a packet is to be delivered to a network monitor, then transmitting the packet to a network segment comprising the network monitor;

storing in a store one or more data structures for determining, using a packet'"'"'s forwarding information, all the network segments, if any, to which the packet is to be transmitted; and

modifying the data structures in response to a command so as to define which packets should be transmitted to which network segments comprising network monitors.

49. The method of claim 45 further comprising generating packets by the apparatus,

wherein the command is a command to transmit to a network segment comprising a network monitor packets generated by the apparatus.

50. The method of claim 45 further comprising generating packets by the apparatus,

wherein the command is a command to transmit to a network segment comprising a network monitor packets that are generated by the apparatus to be transmitted to a selected network segment.

51. The method of claim 45 wherein the command is a command to transmit to a network segment comprising a network monitor packets received from a first selected network segment and transmitted in step (b) to a second selected network segment.

52. The method of claim 45 wherein the command is a command to restore the data structures to a state before an application of any command to transmit any packet to any network segment comprising a network monitor.

53. A method for monitoring a network comprising an apparatus interconnecting a plurality of network segments at least one of which comprises a network monitor, the method comprising:

(a) obtaining, from each packet received by the apparatus, forwarding information to be used in determining the packet destination;

(b) if a packet destination includes a station other than the apparatus, then transmitting the packet to one or more of the network segments in order to deliver the packet to the packet destination; and

(c) if a packet is to be delivered to a network monitor, then transmitting the packet to a network segment comprising the network monitor,

wherein the step (c) comprises applying one or more custom filtering rules to determine whether a packet is to be delivered to a network monitor.