Methods, systems and articles of manufacture to resume a remote desktop session

1. A method to resume a remote desktop session, the method comprising:

multicasting a query to resume the remote desktop session, the query containing a first value representing a user identifier, and the query multicasted from a first computing device to a first intermediate computing device on a first network domain and a second intermediate computing device on a second network domain;

receiving a first response from the first intermediate computing device or a second response from the second intermediate computing device, the first response including a first address stored at the first intermediate computing device for a first remote desktop session corresponding to the user identifier at the first network domain, and the second response including a second address stored at the second intermediate device for a second remote desktop session corresponding to the user identifier at the second network domain; and

selecting to resume, at the first computing device, the first remote desktop session based on the first address or the second remote desktop session based on the second address.

2. A method as defined in claim 1 , further comprising including a public key in the query, wherein the first and second addresses are encrypted using the public key.

3. A method as defined in claim 1 , further comprising computing the first value as a hash of the user identifier.

4. A method as defined in claim 1 , further comprising:

multicasting the query containing the first value to a third intermediate computing device on a third network domain; and

receiving a third response from the third intermediate computing device, the third response including a third address stored at the third intermediate device for a third remote desktop session corresponding to the user identifier at the third network domain, the third remote desktop session being selectable to resume at the first computing device based on the third address.

5. The method as defined in claim 1 , further comprising:

receiving a third address corresponding to the first intermediate computing device and a fourth address corresponding to the second intermediate computing device from a domain name service, the third address and the fourth address being used to multicast the query.

6. A tangible computer-readable medium comprising instructions which, when executed, cause a machine to at least:

multicast a query packet containing a user identifier from a first computing device to a first intermediate computing device on a first network domain and to a second intermediate computing device on a second network domain;

receive a first response packet from the first intermediate computing device or a second response packet from the second intermediate device, the first response packet including a first address stored at the first intermediate computing device for a first remote desktop session corresponding to the user identifier at the first network domain, and the second response packet including a second address stored at the second intermediate device for a second remote desktop session corresponding to the user identifier at the second network domain; and

select to resume, at the first computing device, the first remote desktop session based on the first address or the second remote desktop session based on the second address.

7. A tangible computer-readable medium as defined in claim 6 , further comprising instructions which, when executed, cause the machine to at least:

include a public key in the query packet, wherein the first and second addresses are encrypted using the public key.

8. A tangible computer-readable medium as defined in claim 6 , further comprising instructions which, when executed, cause the machine to at least:

compute the first value as a hash of the user identifier.

9. A tangible computer-readable medium as defined in claim 6 , further comprising instructions which, when executed, cause the machine to at least:

send the query packet containing the first value to a third intermediate computing device on a third network domain; and

receive a third response packet from the third intermediate computing device, the third response packet including a third address stored at the third intermediate device for a third remote desktop session corresponding to the user identifier at the third network domain, the third remote desktop session selectable to resume at the first computing device based on the third address.

10. A tangible computer-readable medium as defined in claim 6 , further comprising instructions which, when executed, cause the machine to at least:

receive a third address corresponding to the first intermediate computing device and a fourth address corresponding to the second intermediate computing device from a domain name service, the machine to use the third address and the fourth address to multicast the query.

11. A system to resume a remote desktop session, the system comprising:

a first directory agent in a first network domain to receive query packets containing a first user identifier, to receive registration packets containing a second user identifier and a first address, and to send a first response packet containing the first address when the first user identifier matches the second user identifier;

a second directory agent in a second network domain to receive query packets containing the first user identifier, to receive registration packets containing a third user identifier and a second address, and to send a second response packet containing the second address when the first user identifier matches the third user identifier; and

a user agent in a third network domain to multicast the query packets containing the first user identifier, to receive the first and second response packets, and to resume the remote desktop session using the first address or the second address.

12. A system as defined in claim 11 , wherein the user agent receives a third address corresponding to the first directory agent and a fourth address corresponding to the second directory agent, and uses the third address and the fourth address to send the query packets.

13. A system as defined in claim 11 , wherein the query packets include a public key.

14. A system as defined in claim 13 , wherein the first directory agent encrypts the first address with the public key before sending the response packets, and the second directory agent encrypts the second address with the public key before sending the response packets.

15. A system as defined in claim 11 , wherein the first directory agent and the second directory agent discards the query packets when the query packets do not contain a public key.