Method, arrangement and system for monitoring a data path in a communication network
A probing method, arrangement, and system for estimating a condition, such as available bandwidth, of a data path in a communication network including multiple nodes are described. A probe-packet sender node transmits probe packets with a sent inter-packet separation and a time-to-live towards an intermediate node. Control message packets are generated by the intermediate node when the time-to-live expires. The probe-packet sender node receives the control message packets and calculates a received inter-packet separation. An estimate of the data path condition can be generated based on the sent inter-packet separation and the received inter-packet separation.
1. A method of estimating a condition in a data path of a communication network, comprising:
providing and transmitting, in a probe node, a first set of probe packets to a destination node during real-time operation of the data path, the first set of probe packets having a first inter-packet separation (IPSsent) and a time-to-live (TTL);
receiving a second set of packets at the probe node generated in an intermediate node when the time-to-live (TTL) for the first set of probe packets expires, the second set of packets having a second inter-packet separation (IPSreceived) and being of a decreased size by comparison with the first set of probe packets;
providing, in response to traversal of the data path by the first set of probe packets, estimation data for use in estimating the condition; and
producing an estimation of the condition, wherein said estimation of the condition is calculated based on a difference between the first inter-packet separation and the second inter-packet separation.
2. The method of claim 1 , wherein the first inter-packet separation and the second inter-packet separation are analysed using an analysis algorithm selected from BART, pathChirp, Spruce and/or Pathload.
3. The method of claim 1 , further comprising:
providing a time stamp for each of the first set of probe packets immediately before and after traversal of the data path.
4. The method of claim 1 , wherein the first set of probe packets are transmitted in sequential trains.
5. The method of claim 1 , wherein the time-to-live (TTL) is set depending on traffic load of the data path.
6. The method of claim 1 , wherein the second set of packets is transmitted using Internet Control Message Protocol (ICMP).
7. The method of claim 6 , wherein the second set of packets comprises ICMP time exceeded packets.
8. A system for estimating a condition in a data path of a communication network, comprising:
at least one processor; and
a non-transitory computer readable medium comprising computer readable program code that when executed by the at least one processor causes the at least one process to perform operations comprising:
providing and transmitting, in a probe node, a first set of probe packets to a destination node during real-time operation of the data path, the first set of probe packets having a first inter-packet separation (IPSsent) and a time-to-live (TTL);
receiving a second set of packets at the probe node generated in an intermediate node when the time-to-live (TTL) for the first set of probe packets expires, the second set of packets having a second inter-packet separation (IPSreceived) and being of a decreased size by comparison with the first set of probe packets;
providing, in response to traversal of the data path by the first set of probe packets, estimation data for use in estimating the condition; and
producing an estimation of the condition, wherein said estimation of the condition is calculated based on a difference between the first inter-packet separation and the second inter-packet separation.
9. The system of claim 8 , wherein the first inter-packet separation and the second inter-packet separation are analysed using an analysis algorithm selected from BART, pathChirp, Spruce and/or Pathload.
10. The system of claim 8 , wherein the operations further comprise:
providing a time stamp for each of the first set of probe packets immediately before and after traversal of the data path.
11. The system of claim 8 , wherein the first set of probe packets are transmitted in sequential trains.
12. The system of claim 8 , wherein the time-to-live (TTL) is set depending on traffic load of the data path.
13. The system of claim 8 , wherein the second set of packets is transmitted using Internet Control Message Protocol (ICMP).
14. The system of claim 13 , wherein the second set of packets comprises ICMP time exceeded packets.