Method of mapping from ATMARP to NHRP

• US 5,809,233 A
• Filed: 12/05/1995
• Issued: 09/15/1998
• Est. Priority Date: 12/05/1995
• Status: Expired due to Term

• Current Assignee: Nokia of America Corporation (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Shur, David Hilton
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): PERVEEN, REHANA
• Application Number:
  US08/567,517
• Time in Patent Office: 1,015 Days
• Field of Search: 370/402, 370/85.13, 370/94.3, 340/825.52, 395/280, 395/200.02, 395/500, 395/416, 395/200.6
• US Class Current: 709/230
• CPC Class Codes: H04L 12/4608 LAN interconnection over ATM networks
• CPC Class Codes: H04L 2012/5615 Network termination, e.g. NT1, NT2, PBX
• CPC Class Codes: H04L 2012/5619 Network Node Interface, e.g. tandem connections, transit switching
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

The present invention is directed to a method of resolving protocol addresses using new protocols. Gateways that map ATMARP packets to NHRP packets are placed in the network to make translations between the two protocols. Therefore the installed base of networks can be maintained, with added functionality. Techniques for handling those areas where the two protocols do not match directly such as sub-address fields, purge packets and holding time expiration are also disclosed.

Claims

1. A method of operating a network utilizing ATMARP and NHRP, said method comprising the steps of:

issuing an ARP-REQuest,

mapping said ARP-REQuest to an NHRP-REQuest,

resolving said NHRP-REQuest thereby generating an NHRP-reply,

Mapping said NHRP-reply to an ATMARP-reply, and

issuing said ATMARP reply.

2. A method as claimed in claim 1 wherein said ARP-REQuest is performed in a source.

3. A method as claimed in claim 1 wherein said mapping said ARP-REQuest to an NHRP-REQuest step is performed in the network.

4. A method as claimed in claim 1 wherein said mapping said NHRP-reply into an ATMARP-reply is performed in a network.

5. A method as claimed in claim 1 wherein said ATMARP-reply is issued to the source.

6. A method as claimed in claim 1 wherein said step of mapping said ARP-REQuest to an NHRP-REQuest is performed by mapping NHRP version bits to current NHRP version, Hopcount bits to zero, checksum bits to checksum of NHRP-REQuest packet, type bits to REQuest bits, mandatory path length bits to length in octets of mandatory part, Q bit to one, A bit to one, S bit to zero, P bit to zero, B bit to zero, Protocol ID bit To ATM ARP protocol type bits, REQuest ID incremented with each new NHRP REQuest, destination address bits to ATMARP target protocol address bits, source address bits to address of gateway, source holding address bits to zero, address type bits to ATM ARP hardware type bits, ATM length bits to ATM ARP source address length bits.

7. A method as claimed in claim 6 wherein said Q bit is set to zero.

8. A method as claimed in claim 1 wherein said step of mapping said NHRP responses to ATMARP responses Is performed by mapping hardware type bits to NHRP address type bits, protocol type bits to NHRP protocol ID bits, sub address type/length bits to zero, operation bits to reply bits when NHRP bit is set to one, target ATM sub address type/length bits to zero, length of source protocol address to four octets, source ATM number bits to source NHRP ATM address source, ATM sub-address to zero, source protocol address bits to senders protocol address bits, target ATM number bits to NHRP ATM target address bits, target ATM subaddress bits to zero, target protocol address bits to NHRP target protocol address bits.

9. A method as claimed in claim 8 wherein said operation bits are set to NAK when NHRP P bit is set to zero.

10. A method as claimed in claim 8 wherein said operation bits are set to NAK when NHRP B bit is set to zero.

11. A method as claimed in claim 8 wherein bit 8 is set to zero.

12. A method as claimed in claim 11 wherein bit 7 is set to zero when ATM length equals 20.

13. A method as claimed in claim 11 wherein bit 7 is set to one.

14. A method as claimed in claim 11 wherein bit 1 through 6 are set to a first six bits of NHRP ATM length.

15. A method as claimed in claim 1 wherein said gateway does not issue a response to the source when NHRP holding time expires.

16. A method as claimed in claim 1 wherein said gateway does not issue a response to the source when purge packet is received.

17. A method as claimed in claim 1 wherein old information in said source due to old information in a NHRP gateway is quenched by issuing a new ATMARP query.

18. A method as claimed in claim 1 wherein a gateway returns a ATM ARP NAK when said gateway processes a non-empty sub-address.

19. A method of translating between a source including a ATMARP client and a network including an NHRP server 1, an NHRP server N, and a ATM/NHRP gateway including a ATMARP server and an NHRP client, said method comprising the steps of:

initiating an ATMARP procedure between said source and said ATMARP client,

issuing an ARP-REQuest from said ATMARP client to said ATM/NHRP gateway,

mapping said ARP-REQuest between said ATMARP server and said NHRP client,

issuing a NHRP REQuest from said NHRP client to said NHRP server 1,

forwarding said NHRP REQuest through said NHRP server 1 to said NHRP server N,

issuing an NHRP-acknowledgment from said NHRP server N,

forwarding said NHRP-acknowledgment through said NHRP server 1 to said ATM/NHRP gateway,

Mapping said NHRP-acknowledgment between said NHRP client and said ATMARP server,

forwarding said ATMARP acknowledgment back to said source.

20. A method of mapping between ATMARP and NHRP utilizing a network, comprising the steps of:

issuing an first ATM command from a source,

translating said first ATM command into an first NHRP command in said network,

resolving said first NHRP command,

converting said resolved first NHRP command into a second ATM command in the network, and

transmitting said second ATM command out of said network back to said source, thereby mapping between ATMARP and NHRP.

21. A communication system for mapping between ATMARP and NHRP, comprising:

a source including an ATMARP client therein, for issuing an ATMARP REQuest,

a gateway including an ATM server, and an NHRP client therein, for receiving said ATMARP REQuest and translating said ATMARP REQuest into a NHRP REQuest, and

at least one server for receiving and resolving said NHRP REQuest.

22. A method as claimed in claim 21 wherein said gateway is located in a network.

23. A method as claimed in claim 22 wherein said server is located in said network.