Methods, nodes and systems in a communication network

1. A method performed by a first node associated with a first domain of a communications network, the method comprising:

sending a first message to a second node associated with a second domain of the communications network, the first message comprising an indication of a resource in the first domain that is available to the second domain, wherein the first message further comprises an anonymized first global unique identifier associated with the first domain;

receiving a second message comprising: an indication of a resource available on a third domain and an anonymized third global unique identifier associated with the third domain;

comparing the third global unique identifier to one or more other global unique identifiers in one or more other received messages to determine one or more matching messages wherein the global unique identifiers in the one or more matching messages are equal to the third global unique identifier; and

determining an estimation of the available resources on the third domain from the resource available on the third domain as indicated in the second message and available resources as indicated in the one or more matching messages.

2. The method of claim 1 , wherein the first message further comprises an indication of the type of resource available in the first domain.

3. The method of claim 1 , further comprising:

comparing the first global unique identifier to the third global unique identifier; and

if the first global unique identifier matches the third global unique identifier, determining that a loop has occurred.

4. The method of claim 1 , wherein determining an estimation of the available resources on the third domain comprises:

summing the resource available on the third domain as indicated in the second message to the available resources as indicated in the one or more matching messages.

5. The method of claim 4 , wherein the second message further comprises an indication of an upper limit of the resource in the third domain and the method further comprises comparing the summation to the upper limit.

6. The method of claim 5 , wherein:

if the summation is less than the upper limit, using the summation as the estimation of the available resources on the third domain; or

if the summation is greater than the upper limit, using the upper limit as the estimation of the available resources on the third domain.

7. The method of claim 6 , further comprising:

including the estimation of the available resources on the third domain and the third global unique identifier in the first message to advertise the estimated available resources on the third domain to the second domain.

8. The method of claim 5 , wherein:

if the summation is greater than the upper limit, determining to overprovision the resource available on the third domain; and

including an indication of the overprovisioned resource in the first message, wherein the overprovision is associated with the first global unique identifier.

9. The method of claim 5 , further comprising:

dividing the summation into a first part and a second part, where the first and second parts are less than the upper limit;

including the first part of the summation in a third message;

including the second part of the summation in a fourth message; and

sending the third and fourth messages from different interfaces of the first domain.

10. The method of claim 1 , wherein the second message further comprises an indication of a path through the communications network from the third domain to the first domain, wherein the path comprises indications of one or more intermediate domains that the indication of a resource available on a third domain has passed through.

11. The method of claim 10 , further comprising:

determining whether the first global unique identifier is indicated in the path.

12. The method of claim 11 , wherein if the first global unique identifier is indicated in the path, the method further comprises:

comparing the path in the second message to another path in a previous message sent by the first node in order to advertise a previously calculated estimation of the available resources on the third domain; and

if the path and the other path are matching, using the indication of a resource available on a third domain from the second message as the estimation of the available resources on the third domain; and

including the indication of a resource available on a third domain from the second message, the anonymized third global unique identifier and the indication of the path in the first message.

13. The method of claim 1 ,

wherein the second message further comprises an indication of a path through the communications network from the third domain to the first domain, and wherein the path comprises indications of one or more intermediate domains that the indication of a resource available on a third domain has passed through;

wherein the method further comprises determining whether the first global unique identifier is indicated in the path, wherein if the first global unique identifier is not indicated in the path, the method further comprises comparing the path in the second message to one or more other paths in the one or more other received messages, and

wherein determining one or more matching messages comprises determining one or more matching messages wherein the global unique identifiers in the one or more matching messages are equal to the third global unique identifier and the paths in the one or more matching messages are different.

14. The method of claim 13 , further comprising:

combining the paths in the one or more matching messages to create a combined path;

modifying the combined path to indicate that the first message has passed through the first domain; and

including the modified combined path in the first message.

15. The method of claim 1 , wherein the first node comprises a resource orchestrator and/or forms part of a hierarchical orchestration system.

16. The method of claim 1 , wherein the first message comprises a resource advertisement.

17. A first node in a communications network, comprising a processor configured to:

send a first message to a second node associated with a second domain of the communications network, the first message comprising an indication of a resource in the first domain that is available to the second domain, wherein the first message further comprises an anonymized first global unique identifier associated with the first domain;

receive a second message comprising: an indication of a resource available on a third domain and an anonymized third global unique identifier associated with the third domain;

compare the third global unique identifier to one or more other global unique identifiers in one or more other received messages to determine one or more matching messages wherein the global unique identifiers in the one or more matching messages are equal to the third global unique identifier; and

determine an estimation of the available resources on the third domain from the resource available on the third domain as indicated in the second message and available resources as indicated in the one or more matching messages.

18. A system in a first domain of a communications network, the system comprising:

a memory comprising instruction data representing a set of instructions; and

a processor configured to communicate with the memory and to execute the set of instructions, wherein the set of instructions, when executed by the processor, cause the processor to:

send a first message to a second node associated with a second domain of the communications network, the first message comprising an indication of a resource in the first domain that is available to the second domain, wherein the first message further comprises an anonymized first global unique identifier associated with the first domain;

receive a second message comprising: an indication of a resource available on a third domain and an anonymized third global unique identifier associated with the third domain;

compare the third global unique identifier to one or more other global unique identifiers in one or more other received messages to determine one or more matching messages wherein the global unique identifiers in the one or more matching messages are equal to the third global unique identifier; and

determine an estimation of the available resources on the third domain from the resource available on the third domain as indicated in the second message and available resources as indicated in the one or more matching messages.