Router which dynamically requests a set of logical network addresses and assigns addresses in the set to hosts connected to the router

• US 6,178,455 B1
• Filed: 04/11/1997
• Issued: 01/23/2001
• Est. Priority Date: 01/17/1997
• Status: Expired due to Term

• Current Assignee: Scientific-Atlanta LLC (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta Incorporated (Cisco Systems, Inc.)
• Inventors: Hrastar, Scott E., Schutte, Mark E.
• Primary Examiner(s): Kim, Kenneth S.
• Application Number:
  US08/843,056
• Time in Patent Office: 1,383 Days
• Field of Search: 370/401, 395/200.53, 395/200.68, 709/226, 709/245, 709/228
• US Class Current: 709/228
• CPC Class Codes: H04H 20/79 using downlink of the CATV systems, e.g. audio broadcast via CATV network
• CPC Class Codes: H04H 60/84 which are fixed telephone networks
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 12/2863 Arrangements for combining access network resources elements, e.g. channel bonding modem pooling H04L25/14; routing of packets H04L45/00; multichannel or multilink protocols H04L69/14
• CPC Class Codes: H04L 12/2872 Termination of subscriber connections
• CPC Class Codes: H04L 12/2874 Processing of data for distribution to the subscribers
• CPC Class Codes: H04L 12/5692 Selection among different networks
• CPC Class Codes: H04L 2101/604 Address structures or formats
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 41/0213 Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 41/0663 Performing the actions predefined by failover planning, e.g. switching to standby network elements
• CPC Class Codes: H04L 41/0677 Localisation of faults
• CPC Class Codes: H04L 61/50 Address allocation
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 61/5061 Pools of addresses
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04N 21/25816 : involving client authentication restricting access to computer systems by authenticating users using a predetermined code G06F21/33; cryptographic authentication protocols H04L9/32; networks authentication protocols H04L63/08; authentication in wireless network security H04W12/06
• CPC Class Codes: H04N 21/42676 : for modulating an analogue carrier signal to encode digital information or demodulating it to decode digital information, e.g. ADSL or cable modem
• CPC Class Codes: H04N 21/6118 : involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/6168 : involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 7/17309 : Transmission or handling of upstream communications

Abstract

The problem of wasting IP addresses by statically assigning them to hosts is solved as follows: when a cable router or RF modem becomes active, it sends a message requesting a set of IP addresses from the head end, which dynamically assigns the set of IP addresses and sends a message comprising the set of IP addresses to the cable router or RF modem. The cable router or RF modem then responds to requests by the hosts for IP addresses by assigning them IP addresses from the set. Furthermore, the set of IP addresses is released when the session terminates with the cable router or RF modem.

Claims

1. A method employed in a router which is coupled between a first bidirectional link and a second bidirectional link of dynamically assigning a logical internet protocol network address to a host on the second bidirectional link, the method comprising the steps performed in the router of:

obtaining a set of logical internet protocol network addresses for hosts on the second bidirectional link from a logical address assignment agent that dynamically assigns the set of logical internet protocol network addresses and is accessible via the first bidirectional link, the set of logical internet protocol network addresses being obtained by sending a request to the logical address assignment agent, the request specifying a number of logical internet protocol network addresses to be obtained, the number of logical internet protocol network addresses indicating how many logical internet protocol addresses are to be returned from the logical address assignment agent in the set of logical internet protocol network addresses; and

responding to a request from a host for a logical internet protocol network address by assigning one of the set of logical internet protocol network addresses to the host.

2. The method of claim 1, further comprising the steps of:

assigning said host a temporary logical internet protocol network address while said router obtains said set of dynamically assignable logical internet protocol network addresses.

3. The method of claim 1, wherein said first bidirectional link is a Point-to-Point Protocol (PPP) link established between said router and a telephone modem.

4. The method of claim 2, further comprising the steps of:

transferring said host'"'"'s authentication information via said first bidirectional link to a telephone modem; and

transferring said authentication information via said telephone modem to an authorization agent wherein said authorization agent tests the validity of said authentication information.

5. The method of claim 4 wherein said authorization agent executes on a control server.

6. The method of claim 4, wherein said logical address assignment agent executes on a control server, said control server comprising a list of assigned and unassigned logical internet protocol network addresses.

7. The method of claim 4, further comprising the steps of:

assigning dynamically a logical internet protocol network address to said router wherein said router can use TCP/IP protocols;

implementing said logical address assignment agent to respond to a request by said router for said set of dynamically assignable logical internet protocol network addresses; and

returning to said router said set of dynamically assignable logical internet protocol network addresses via said telephone modem and said first bidirectional link.

8. The method of claim 7, wherein said set of dynamically assignable logical internet protocol network addresses is at least one logical internet protocol network addresses assignable to any said host coupled to said router via said second bidirectional link that makes at least one request for said at least one logical internet protocol network address.

9. The method of claim 7, further comprising the step of:

responding to a request from said host to said router via said second bidirectional link for a new logical internet protocol network address prior to the expiration of said temporary logical internet protocol network address wherein said host is assigned said new logical internet protocol network address from said set of dynamically assignable logical internet protocol network addresses.

10. The method of claim 9, further comprising the steps of:

transferring digital data received along a unidirectional link coupled to said router along said second bidirectional link to said host wherein said digital data is addressed to said new logical internet protocol network address assigned to said host.

11. The method of claim 1, further comprising the steps of:

implementing a telephone modem coupled to said router via said first bidirectional link; and

implementing a telecommunication connection between said router and said telephone modem via said first bidirectional link.

12. The method of claim 11, wherein said telephone modem is communicably coupled to a public switched telephone network.

13. The method of claim 6, wherein said logical address assignment agent includes a dynamic host configuration protocol (DHCP) server.

14. The method of claim 6, further comprising the step of:

implementing an internet protocol (IP) manager on said control server to maintain said list of assigned and unassigned logical internet protocol network addresses.

15. A method employed in a router which is coupled between a first path and a second path of dynamically assigning a logical internet protocol network address to a host on said second path, the method comprising the steps performed in the router of:

obtaining a set of logical internet protocol network addresses for hosts on said second path from a logical address assignment agent that dynamically assigns said set of logical internet protocol network addresses and is accessible via said first path, the set of logical internet protocol network addresses being obtained by sending a request to the logical address assignment agent, the request specifying a number of logical internet protocol network addresses to be obtained, the number of logical internet protocol network addresses indicating how many logical internet protocol addresses are to be returned from the logical address assignment agent in the set of logical internet protocol network addresses; and

responding to a request from a host for a logical internet protocol network address by dynamically assigning one of said set of logical internet protocol network addresses to said host.

16. The method of claim 15, further comprising the steps of:

assigning said host a temporary logical internet protocol network address while said router obtains said set of dynamically assignable logical internet protocol network addresses.

17. The method of claim 16, further comprising the step of:

transferring a host'"'"'s authentication information from said router via said first path to an authentication agent wherein said authentication agent tests the validity of said authentication information.

18. The method of claim 17 wherein said authorization agent executes on a control server.

19. The method of claim 17, wherein said logical address assignment agent executes on a control server, said control server comprising a list of assigned and unassigned logical internet protocol network addresses.

20. The method of claim 17, further comprising the steps of:

assigning dynamically a logical internet protocol network address to said router wherein said router can use TCP/IP protocols;

implementing said logical address assignment agent to respond to a request by said router for said set of dynamically assignable logical internet protocol network addresses; and

returning to said router said set of dynamically assignable logical internet protocol network addresses via said first path.

21. The method of claim 20, wherein said set of dynamically assignable logical internet protocol network addresses is at least one logical internet protocol network addresses assignable to any said host coupled to said router via said second path that makes at least one request for said at least one logical internet protocol network address.

22. The method of claim 20, further comprising the step of:

responding to a request from said host via said second path for a new logical internet protocol network address prior to the expiration of said temporary logical internet protocol network address wherein said host is assigned said new logical internet protocol network address from said set of dynamically assignable logical internet protocol network addresses.

23. The method of claim 22, further comprising the step of:

transferring digital data received by said router addressed to said new logical internet protocol network address assigned to said host along said second path to said host.

24. The method of claim 19, wherein said logical address assignment agent includes a DHCP server.

25. The method of claim 19, further comprising the step of:

implementing an IP manager on said control server to maintain said list of assigned and unassigned logical internet protocol network addresses.

26. The method of claim 25, further comprising:

implementing a simple network management protocol (SNMP) agent to execute on said control server and to assist said IP manager in assigning and deassigning said logical internet protocol network addresses.

27. The method of claim 23, further comprising the steps of:

detecting when a last host coupled to said router via said second path terminates communication with said router wherein no host is in communication with said router via said second path; and

terminating all incoming and outgoing communication along said first path wherein said set of dynamically assignable logical internet protocol network addresses are released from assignment to said router and become available for reassignment.

28. A system employed in a router which is coupled between a first path and a second path for dynamically assigning a logical internet protocol network address to a host on the second path, comprising:

logic configured to obtain a set of dynamically assigned logical internet protocol network addresses for hosts on said second path, the set of logical internet protocol network addresses obtained by sending a request to the logical address assignment agent, the request specifying a number of logical internet protocol network addresses to be obtained, the number of logical internet protocol network addresses indicating how many logical internet protocol addresses are to be returned from the logical address assignment agent in the set of logical internet protocol network addresses;

a logical address assignment agent that dynamically assigns said set of logical internet protocol network addresses and is accessible via said first path; and

said router responding to a request from said host for one of said logical internet protocol network address by dynamically assigning one of said set of logical internet protocol network addresses to said host.

29. The system of claim 28, further comprising:

logic configured to assign a temporary logical internet protocol network address to said host while said router obtains said set of dynamically assignable logical internet protocol network addresses.

30. The system of claim 29, further comprising:

host authentication information transferred via said first path to an authorization agent, wherein said authorization agent tests the validity of said authentication information.

31. The system of claim 30 wherein said authorization agent executes on a control server.

32. The system of claim 30, wherein said logical address assignment agent executes on a control server, said control server maintaining a list of assigned and unassigned logical internet protocol network addresses.

33. The system of claim 30, further comprising:

logic configured to dynamically assign a logical internet protocol network address to said router by said logical address assignment wherein said router can use TCP/IP protocols;

a request to said logical address assignment agent by said router for assignment of said set of dynamically assignable logical internet protocol network addresses; and

logic configured to receive said set of dynamically assignable logical internet protocol network addresses returned to said router via said first path.

34. The system of claim 33, wherein said set of dynamically assignable logical internet protocol network addresses is at least one logical internet protocol network addresses assignable to any said host coupled to said router via said second path that makes at least one request for said at least one logical internet protocol network address.

35. The system of claim 33, further comprising:

a request from said host via said second path for a new logical internet protocol network address prior to the expiration of said temporary logical internet protocol network address wherein said host is assigned said new logical internet protocol network address from said set of dynamically assignable logical internet protocol network addresses.

36. The system of claim 35, further comprising:

digital data received by said router addressed to said new logical internet protocol network assigned to said host wherein said digital data is transferred along said second path to said host.

38. The system of claim 32, wherein said logical address assignment agent includes a DHCP server.

39. The system of claim 32, further comprising the step of:

logic configured to implement an IP manager on said control server to maintain said list of assigned and unassigned logical internet protocol network addresses.

40. The system of claim 39, further comprising:

logic configured to implement an a SNMP agent to execute on said control server and to assist said IP manager in assigning and deassigning said logical internet protocol network addresses.

41. The system of claim 36, further comprising:

logic configured to detect when a last host coupled to said router via said second path terminates communication with said router wherein no host is in communication with said router via said second path; and

logic configured to terminate all incoming and outgoing communication along said first path wherein said set of dynamically assignable logical internet protocol network addresses are released from assignment to said router and become available for reassignment.

42. The system of claim 41, wherein said set of dynamically assignable logical internet protocol network addresses are released from assignment to said router by a DHCP message sent to a logical address assignment agent instructing the release.

43. The system of claim 36, further comprising:

logic configured to detect when said router is inactive for a prescribed time; and

logic configured to deassign said set of logical internet protocol network addresses from said router and make said set of logical internet protocol network addresses available for reassignment to another router upon request.

44. The system of claim 36, further comprising:

logic configured to monitor the period of time that a logical internet protocol network addresses is assigned to said router; and

logic configured to deassign any from said router said logical internet protocol network addresses if said router fails to notify said logical address assignment agent of said router'"'"'s continued utilization of said logical internet protocol network address within a preset time period wherein said logical internet protocol network address is made available for reassignment to another router upon request.

37. A router which is coupled between a first path and a second path, comprising:

means for obtaining a set of dynamically assignable logical internet protocol network addresses for hosts on said second path from a logical address assignment agent, the set of logical internet protocol network addresses being obtained by sending a request to the logical address assignment agent, the request specifying a number of logical internet protocol network addresses to be obtained, the number of logical internet protocol network addresses indicating how many logical internet protocol addresses are to be returned from the logical address assignment agent in the set of logical internet protocol network addresses; and

means for dynamically assigning said host on said second path upon request one of said logical internet protocol network addresses dynamically assigned to said router.

45. A router coupled between a first link and a second link for dynamically obtaining and assigning a logical internet protocol network address to at least one host on the second link, comprising:

logic configured to dynamically obtain on the first link a set of logical internet protocol network addresses for at least one host on the second link, the set of logical internet protocol network addresses being obtained by sending a request to a logical address assignment agent, the request specifying a number of logical internet protocol network addresses to be obtained, the number of logical internet protocol network addresses indicating how many logical internet protocol addresses are to be returned from the logical address assignment agent in the set of logical internet protocol network addresses; and

logic configured to respond to a request from said host and dynamically assign a logical internet protocol address from one of the set of logical internet protocol network addresses to said host on the second link.

46. The router of claim 45, wherein said router only obtains said set of logical internet protocol network addresses after at least one of said hosts makes a request for a logical internet protocol network address.

47. The router of claim 45, wherein said router utilizes DCHP protocol to obtain said set of logical internet protocol network addresses.

48. The router of claim 45, further comprising:

logic configured to assign a temporary logical internet protocol network address to said host while said router obtains said set of dynamically assignable logical internet protocol network addresses.

49. The router of claim 48, further comprising:

a telephone modem coupled to said router via said first link; and

a telecommunication connection implemented between said router and said telephone modem via said first link.

50. The router of claim 49, wherein said router and said telephone modem a establish Point-to-Point Protocol (PPP) link.

51. The router of claim 49, further comprising:

host authentication information transmitted via said first link to said telephone modem; and

an authorization agent accessible by said telephone modem wherein said authorization agent receives said authentication information from said telephone modem and tests the validity of said authentication information.

52. The router of claim 51, wherein said authorization agent executes on a control server.

53. The router of claim 51, wherein said logical address assignment agent executes on a control server, said control server comprising a list of assigned and unassigned logical internet protocol network addresses.

54. The router of claim 53, wherein said logical address assignment agent includes a DHCP server.

55. The router of claim 53, further comprising the step of:

an IP manager executed on said control server to maintain said list of assigned and unassigned logical internet protocol network addresses.

56. The router of claim 55, further comprising:

a SNMP agent executed on said control server and to assist said IP manager in assigning and deassigning said logical internet protocol network addresses.

57. The router of claim 51, further comprising:

a logical internet protocol network address dynamically assigned to said router by said logical address assignment agent wherein said router can use TCP/IP protocols;

a request to said logical address assignment agent by said router for assignment of said set of dynamically assignable logical internet protocol network addresses; and

said set of dynamically assignable logical internet protocol network addresses returned to said router via said telephone modem and said first link.

58. The router of claim 57, wherein said set of dynamically assignable logical internet protocol network addresses is at least one logical internet protocol network addresses assignable to any said host coupled to said router via said second link that makes at least one request for said at least one logical internet protocol network address.

59. The router of claim 57, further comprising:

a request from said host to said router via said second link for a new logical internet protocol network address prior to the expiration of said temporary logical internet protocol network address wherein said host is assigned said new logical internet protocol network address from said set of dynamically assignable logical internet protocol network addresses.

60. The router of claim 59, further comprising:

a unidirectional link coupled to said router; and

digital data received by said router along said unidirectional link that is addressed to said new logical internet protocol network address assigned to said host wherein said digital data is transferred along said second link to said host.

61. The router of claim 60, further comprising:

logic configured to detect when a last host coupled to said router via said second path terminates communication with said router wherein no host is in communication with said router via said second path; and

logic configured to terminate communication along said first path wherein said set of dynamically assignable logical internet protocol network addresses are released from assignment to said router and become available for reassignment.

62. The router of claim 61, wherein said set of dynamically assignable logical internet protocol network addresses are released from assignment to said router by a DHCP message sent to said logical address assignment agent instructing the release.