Router for use with a link that has a set of concurrent channels

• US 6,618,353 B2
• Filed: 04/11/1997
• Issued: 09/09/2003
• Est. Priority Date: 01/17/1997
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta Incorporated (Cisco Systems, Inc.)
• Inventors: Hrastar, Scott E., Merrill, Todd A., Bowcutt, Roy A., Schutte, Mark E.
• Primary Examiner(s): Marcelo, Melvin
• Assistant Examiner(s): KWOH, JASPER C
• Application Number:
  US08/838,833
• Publication Number:
  US 20010012292A1
• Time in Patent Office: 2,342 Days
• Field of Search: 370/389, 370/392, 370/401, 370/437, 370/480, 370/485, 370/486, 370/487, 370/216, 370/217, 370/244, 370/227, 370/432, 370/436, 370/478, 370/490, 375/275, 375/222, 348/12, 348/14.01, 348/552, 348/553, 709/225, 709/226, 709/203, 709/207, 709/202, 709/218, 709/219, 709/228, 709/245
• US Class Current: 370/225
• 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

An asymmetrical network for coupling customer-premises Internet hosts such as personal computers to the Internet. The head end of a CATV system has a high-bandwidth connection to the Internet. The down link connecting the personal computers to the Internet is the cables provided by the CATV system; the up link is a telephone connection to the head end. A router is connected to the down link by means of an RF modem, to the up link by means of an analog modem, and to a LAN which is connected to the Pcs. The router routes IP packets for the hosts that are received on the CATV cable to the hosts via the LAN; it routes IP packets from the hosts that are destined for the Internet to the head end via the telephone line. The asymmetrical network conserves IP addresses and addresses on the CATV cable by dynamically allocating the IP addresses for an RF modem'"'"'s hosts and an address on the CATV cable for the RF modem in response to a request made by the RF modem via the telephone line. It further saves IP addresses by assigning a non-unique IP address to the router for use inside the LAN. When the CATV system fails, the asymmetrical network automatically begins to use the telephone line as both the up link and the down link, and when the CATV system is restored, the asymmetrical network automatically returns to using the CATV cable as the down link and the telephone line as the up link. A further feature of the asymmetrical network is that the head end components and the RF modem have IP addresses, so that standard TCP/IP protocols can be used to control the asymmetrical network.

Claims

1. A router coupled between a first link, a second link, and a third link having at least one host, the router comprising:

a receiver for the first link, the first link comprising a set of concurrent channels wherein a plurality of packets are capable of being transmitted simultaneously on a plurality of channels of the set of concurrent channels, the receiver capable of being set to receive at least one channel of the set of concurrent channels and reading data received thereon; and

a controller which responds to a message received in the second link, the message comprising information that specifies at least one channel of the set of concurrent channels in the first link, the at least one channel being a source of packets having a logical address, the controller responding by assigning the logical address to the host, by setting the receiver to receive the specified at least one channel, and thereupon by routing packets received thereon that have the host'"'"'s logical address to the host via the third link, wherein the message received by the controller is communicated using a Dynamic Host Configuration Protocol (DHCP).

2. The apparatus of claim 1, wherein the message communicated using the DHCP protocol is carried in at least one DHCP datagram.

3. The apparatus of claim 2, wherein the at least one DHCP datagram uses at least one vendor-specific option.

4. A router coupled between a first link, a second link, and a third link having at least one host, the router comprising:

a receiver for the first link, the first link comprising a set of concurrent channels wherein a plurality of packets are capable of being transmitted simultaneously on a plurality of channels of the set of concurrent channels, the receiver capable of being set to receive at least one channel of the set of concurrent channels and reading data received thereon; and

a controller which responds to a message received in the second link, the message comprising information that specifies at least one channel of the set of concurrent channels in the first link, the at least one channel being a source of packets having a logical address, the controller responding by assigning the logical address to the host, by setting the receiver to receive the specified at least one channel, and thereupon by routing packets received thereon that have the host'"'"'s logical address to the host via the third link, wherein the controller uses a Dynamic Host Configuration Protocol (DHCP) for assigning the logical address to the host.

5. A method employed in a router, the router being coupled between a first link, a second link, and a third link having at least one host, the method comprising the steps performed in the router of:

receiving a message on the second link that comprises information which specifies at least one channel of a set of concurrent channels in the first link as a source of packets having a logical address, the first link comprising the set of concurrent channels wherein a plurality of packets are capable of being transmitted simultaneously on a plurality of channels of the set of concurrent channels, the specified at least one channel being one for which a receiver in the router is capable of being set to receive the channel and reading the data received thereon; and

responding to the message received in the second link by assigning the logical address to the host, by setting the receiver to receive the specified at least one channel, and thereupon by routing packets received thereon that have the host'"'"'s logical address to the host via the third link, wherein the message received by the controller is communicated using a Dynamic Host Configuration Protocol (DHCP).

6. The method of claim 5, wherein the message communicated using the DHCP protocol is carried in at least one DHCP datagram.

7. The method of claim 6, wherein the at least one DHCP datagram uses at least one vendor-specific option.

8. A method employed in a router, the router being coupled between a first link, a second link, and a third link having at least one host, the method comprising the steps performed in the router of:

receiving a message on the second link that comprises information which specifies at least one channel of a set of concurrent channels in the first link as a source of packets having a logical address, the first link comprising the set of concurrent channels wherein a plurality of packets are capable of being transmitted simultaneously on a plurality of channels of the set of concurrent channels, the specified at least one channel being one for which a receiver in the router is capable of being set to receive the channel and reading the data received thereon; and

responding to the message received in the second link by assigning the logical address to the host, by setting the receiver to receive the specified at least one channel, and thereupon by routing packets received thereon that have the host'"'"'s logical address to the host via the third link, wherein the controller uses a Dynamic Host Configuration Protocol (DHCP) for assigning the logical address to the host.

9. A method for receiving dynamic assignment of an RF channel to an RF modem, the RF modem connected to an RF medium that is part of a cable data network with a CATV head end, the method comprising the steps performed in the RF modem of:

listening for at least one packet by tuning to a first RF channel of a plurality of channels of the RF medium on the cable data network to receive the at least one packet, wherein the received at least one packet has identification information associated therewith, and the plurality of channels have packets with identification information associated therewith transmitted therein, wherein regardless of when the RF modem is configured for communications between the CATV head end and the RF modem over the RF medium, the CATV head end repetitively transmits the at least one packet and repetitively transmits identification information associated with the packets of the plurality of channels;

obtaining identification of a second RF channel in the RF medium based at least upon the identification information associated with the at least one packet, the second RF channel being the dynamically assigned RF channel for the RF modem;

tuning at least one tuner in the RF modem to the second RF channel; and

utilizing the second RF channel for communications between the CATV head end and the RF modem, wherein the utilizing step occurs after the RF modem has listened, obtained, and tuned as at least part of an initial setup process for configuring the RF modem for communications between the CATV head end and the RF modem over the RF medium.

10. The method of claim 9, wherein the first RF channel and the second RF channel are different.

11. The method of claim 9, wherein the RF modem is able to dynamically change its RF channel tuning in the listening step.

12. The method of claim 9, wherein the listening step comprises the steps of:

decoding a portion of the information in the at least one packet, the portion of the information comprising a specifier for the RF medium in the cable data network; and

maintaining the specifier for the RF medium to allow the specifier to be communicated by the RF modem to the CATV head end in the obtaining step.

13. The method of claim 12, wherein the specifier is a stream ID (STRID).

14. The method of claim 12, wherein the specifier and a frequency associated with an RF channel comprise information that uniquely identifies the RF medium.

15. The method of claim 9, wherein the identification information associated with the at least one packet is a stream ID (STRID).

16. The method of claim 9, wherein the identification information associated with the packets of the plurality of channels is at least one stream ID (STRID).

17. The method of claim 9, wherein the obtaining step comprises the steps of:

requesting information for assignment of the second RF channel from the CATV head end; and

receiving the information from the CATV head end.

18. The method of claim 17, wherein the requesting step is performed by sending information in a second medium other than the RF medium.

19. The method of claim 18, wherein the second medium is a PSTN medium.

20. The method of claim 17, wherein the requesting step and the receiving step utilize a Dynamic Host Configuration Protocol (DHCP).

21. The method of claim 20, wherein the DHCP protocol communicates using at least one DHCP datagram.

22. The method of claim 21, wherein the at least one DHCP datagram communicates information using a vendor-specific option.

23. The method of claim 17, wherein the requesting step further comprises requesting an IP address for the RF modem, and the receiving step further comprises receiving an IP address for the RF modem.

24. The method of claim 17, wherein the receiving step further comprises receiving information about where the RF modem can obtain current firmware.

25. The method of claim 9, wherein the second RF channel is uni-directional.

26. The method of claim 25, wherein the second RF channel can communicate information from the CATV head end to the RF modem.

27. The method of claim 9, wherein the at least one packet is at least one superframe.

28. The method of claim 9, wherein the at least part of an initial setup process is completed before communications between the CATV head end and the RF modem over the RF medium are utilized to initiate the establishment of communication over the RF medium between at least one arbitrary host and at least one user of the RF modem.

29. The method of claim 28, wherein the at least one user of the RF modem is at least one person who uses the RF modem by operating at least one host connected to the RF modem.

30. The method of claim 28, wherein the at least one arbitrary host is selected by decisions of the at least one user of the RF modem to communicate with a host at an arbitrary and valid IP address.

31. The method of claim 28, wherein the at least one arbitrary host contains images that are retrievable by the at least one user of the RF modem.

32. The method of claim 9, wherein the RF modem forwards packets over the RF medium between the CATV head end and an at least one host connected to the RF modem.

33. The method of claim 9, wherein the first RF channel is one of a set of concurrent RF channels in the RF medium, each RF channel of the set of concurrent RF channels being separated by frequency from the other RF channels in the set of concurrent RF channels.

34. The method of claim 9, wherein the second RF channel is one of a set of concurrent RF channels in the RF medium, each RF channel of the set of concurrent RF channels being separated by frequency from the other RF channels in the set of concurrent RF channels.

35. An RF modem which receives dynamic assignment of an RF channel, the RF modem connected to an RF medium that is part of a cable data network with a CATV head end, the RF modem comprising:

logic embodied in a computer readable medium configured to listen for at least one packet by tuning to a first RF channel of a plurality of channels of the RF medium on the cable data network to receive the at least one packet, wherein the received at least one packet has identification information associated therewith, and the plurality of channels have packets with identification information associated therewith transmitted therein, wherein regardless of when the RF modem is configured for communications between the CATV head end and the RF modem over the RF medium, the CATV head end repetitively transmits the at least one packet and repetitively transmits identification information associated with the packets of the plurality of channels;

logic embodied in a computer readable medium configured to obtain identification of a second RF channel in the RF medium based at least upon the identification information associated with the at least one packet, the second RF channel being the dynamically assigned RF channel for the RF modem;

logic embodied in a computer readable medium configured to tune at least one tuner in the RF modem to the second RF channel; and

logic embodied in a computer readable medium configured to utilize the second RF channel for communications between the CATV head end and the RF modem, wherein the logic configured to utilize the second RF channel utilizes the second RF channel after the logic configured to listen, obtain, and tune has operated as at least part of an initial setup process for configuring the RF modem for communications between the CATV head end and the RF modem over the RF medium.

36. The apparatus of claim 35, wherein the first RF channel and the second RF channel are different.

37. The apparatus of claim 35, wherein the RF modem is able to dynamically change its RF channel tuning.

38. The apparatus of claim 35, wherein the logic embodied in a computer readable medium to listen further includes logic configured to:

decode a portion of the information in the at least one packet, the portion of the information comprising the identification information associated with the at least one packet, the identification information being a specifier for the RF medium in the cable data network; and

maintain the specifier for the RF medium to allow the specifier to be communicated by the RF modem to the CATV head end.

39. The apparatus of claim 38, wherein the specifier is a stream ID (STRID).

40. The apparatus of claim 38, wherein the specifier and a frequency associated with an RF channel comprise information that uniquely identifies the RF medium.

41. The apparatus of claim 35, wherein the identification information associated with the at least one packet is a stream ID (STRID).

42. The apparatus of claim 35, wherein the identification information associated with the packets of the plurality of channels is at least one stream ID (STRID).

43. The apparatus of claim 35, wherein the logic embodied in a computer readable medium configured to obtain further includes logic configured to:

request information for assignment of the second RF channel from the CATV head end; and

receive the information from the CATV head end.

44. The apparatus of claim 43, wherein the logic configured to request information sends information in a second medium other than the RF medium.

45. The apparatus of claim 44, wherein the second medium is a PSTN medium.

46. The apparatus of claim 43, wherein the logic configured to request information and the logic configured to receive the information utilize a Dynamic Host Configuration Protocol (DHCP).

47. The apparatus of claim 46, wherein the DHCP protocol communicates using at least one DHCP datagram.

48. The apparatus of claim 47, wherein the at least one DHCP datagram communicates information using a vendor-specific option.

49. The apparatus of claim 43, wherein the logic configured to request information further includes logic to request an IP address for the RF modem, and the logic configured to receive information further includes logic to receive an IP address for the RF modem.

50. The apparatus of claim 43, wherein the logic configured to receive information further includes logic to receive information about where the RF modem can obtain current firmware.

51. The apparatus of claim 35, wherein the second RF channel is uni-directional.

52. The apparatus of claim 51, wherein the second RF channel can communicate information from the CATV head end to the RF modem.

53. The apparatus of claim 35, wherein the first RF channel is one of a set of concurrent RF channels in the RF medium, each RF channel of the set of concurrent RF channels being separated by frequency from the other RF channels in the set of concurrent RF channels.

54. The apparatus of claim 35, wherein the second RF channel is one of a set of concurrent RF channels in the RF medium, each RF channel of the set of concurrent RF channels being separated by frequency from the other RF channels in the set of concurrent RF channels.

55. The apparatus of claim 35, wherein the at least one packet is at least one superframe.

56. The apparatus of claim 35, wherein the at least part of an initial setup process is completed before communications between the CATV head end and the RF modem over the RF medium are utilized to initiate the establishment of communication over the RF medium between at least one arbitrary host and at least one user of the RF modem.

57. The apparatus of claim 56, wherein the at least one user of the RF modem is at least one person who uses the RF modem by operating at least one host connected to the RF modem.

58. The apparatus of claim 56, wherein the at least one arbitrary host is selected by decisions of the at least one user of the RF modem to communicate with a host at an arbitrary and valid IP address.

59. The apparatus of claim 56, wherein the at least one arbitrary host contains images that are retrievable by the at least one user of the RF modem.

60. The apparatus of claim 35, wherein the RF modem forwards packets over the RF medium between the CATV head end and an at least one host connected to the RF modem.

61. A method for communicating a dynamic assignment of an RF channel to an RF modem, the RF modem connected to an RF medium that is part of a cable data network with a CATV head end, the method comprising the steps performed in the CATV head end of:

transmitting information repetitively on a first RF channel in the RF medium of the cable data network, the information being transmitted with at least one packet, the information being repetitively transmitted over the RF medium by the CATV head end regardless of when the RF modem is being configured for communications between the CATV head end and the RF modem over the RF medium;

receiving a request from the RF modem for initial setup, the request being based at least upon information communicated with the at least one packet;

providing information to the RF modem to allow the RF modem to obtain an assignment of a second RF channel in the RF medium; and

utilizing the second RF channel for communications between the CATV head end and the RF modem, wherein the utilizing step occurs after the RF modem has obtained an assignment of the second RF channel as at least part of an initial setup process for configuring the RF modem for communications between the CATV head end and the RF modem over the RF medium.

62. The method of claim 61, wherein the repetitively transmitted information comprises a specifier for the RF medium in the cable data network.

63. The method of claim 62, wherein the specifier for the RF medium is a stream ID (STRID).

64. The method of claim 61, wherein the receiving step is performed by receiving information in a second medium other than the RF medium and wherein the providing step is performed by providing information in the second medium.

65. The method of claim 64, wherein the second medium is a PSTN medium.

66. The method of claim 61, wherein the second RF channel is uni-directional.

67. The method of claim 66, wherein the second RF channel can communicate information from the CATV head end to the RF modem.

68. The method of claim 61, wherein the receiving step and the providing step utilize a Dynamic Host Configuration Protocol (DHCP).

69. The method of claim 61, wherein the information provided to the RF modem is in at least one second packet.

70. The method of claim 69, wherein the information provided to the RF modem in the at least one second packet allows the RF modem to obtain an assignment of a second RF channel in the RF medium by decoding the information in the at least one second packet to directly determine the dynamically assigned second RF channel, the information in the at least one second packet comprising the identification of the second RF channel.

71. The method of claim 61, wherein the at least part of an initial setup process is completed before communications between the CATV head end and the RF modem over the RF medium are utilized to initiate the establishment of communication over the RF medium between at least one arbitrary host and at least one user of the RF modem.

72. The method of claim 71, wherein the at least one arbitrary host is selected by decisions of the at least one user of the RF modem to communicate with a host at an arbitrary and valid IP address.

73. The method of claim 61, wherein the receiving step further comprises receiving a request for an IP address for the RF modem, and the providing step further comprises providing an IP address for the RF modem.

74. The method of claim 61, wherein the providing step further comprises providing information about where the RF modem can obtain current firmware.