The IESG has approved the following document: - 'Alternate Marking method for passive and hybrid performance monitoring' (draft-ietf-ippm-alt-mark-14.txt) as Experimental RFC This document is the product of the IP Performance Measurement Working Group. The IESG contact persons are Mirja Kühlewind and Spencer Dawkins. A URL of this Internet Draft is: https://datatracker.ietf.org/doc/draft-ietf-ippm-alt-mark/ Technical Summary This document describes a method to perform packet loss, delay and jitter measurements on live traffic. This method is based on Alternate Marking (Coloring) technique. A report on the operational experiment done at Telecom Italia is explained in order to give an example and show the method applicability. This technique can be applied in various situations as detailed in this document and could be considered passive or hybrid depending on the application. Working Group Summary The WG process as it relates to this document has been smooth and without major controversies. The WGLC was also smooth, and the editors have been very responsive and diligent in incorporating all the WGLC comments in a timely fashion. While the document contain a single Editor, it lists more than five authors. The history and rationale for that is as follows: the ideas on this methodology originated and were introduced to the IETF from two I-Ds: draft-cociglio-mboned-multicast-pm and draft-tempia-opsawg-p3m. Most recently, draft-tempia-opsawg-p3m targeted the IPPM WG, and was renamed to draft-tempia-ippm-p3m. After adotpion in IPPM, it merged with the descriptive portions of draft-chen-ippm-coloring-based-ipfpm-framework (the architectural portions were deamed out of scope for IPPM. This union added more value to the work because it completed the technical explanation of the methodology. Consequently new authors joined the draft after this merge. Document Quality There is both significant and broad support for the methods defined in this document. This manifests itself in the number of protocols that are producing specifications (in other working groups) utilizing these methods natively with them. For example, BIER, MPLS, etc. This document has 12 other documents currently referencing it, as per <https://datatracker.ietf.org/doc/draft-ietf-ippm-alt-mark/referencedby/>. Further, there are many vendors (chip vendors, networking software vendors, etc.) either with implementations, roadmaps, or plans to implement these methods. Personnel Carlos Pignataro is the Document Shepherd. Spencer Dawkins is the Responsible Area Director. RFC Editor Note OLD o no interoperability issues: the features required to experiment and test the method (as described in Section 5.1) are available on all current routing platforms. Both a centarlized or distributed solution can be used to harvest data from the routers. NEW o no interoperability issues: the features required to experiment and test the method (as described in Section 5.1) are available on all current routing platforms. Both a centralized or distributed solution can be used to harvest data from the routers. OLD Traffic coloring could be done by R1 itself or it is already done before. R1 needs two counters, C(A)R1 and C(B)R1, on its egress interface: C(A)R1 counts the packets with color A and C(B)R1 counts those with color B. As long as traffic is colored A, only counter C(A)R1 will be incremented, while C(B)R1 is not incremented; vice versa, when the traffic is colored as B, only C(B)R1 is incremented. C(A)R1 and C(B)R1 can be used as reference values to determine the packet loss from R1 to any other measurement point down the path. Router R2, similarly, will need two counters on its ingress interface, C(A)R2 and C(B)R2, to count the packets received on that interface and colored with color A and B respectively. When an A block ends, it is possible to compare C(A)R1 and C(A)R2 and calculate the packet loss within the block; similarly, when the successive B block terminates, it is possible to compare C(B)R1 with C(B)R2, and so on for every successive block. NEW Traffic coloring can be done by R1 itself if the traffic is not already colored. R1 needs two counters, C(A)R1 and C(B)R1, on its egress interface: C(A)R1 counts the packets with color A and C(B)R1 counts those with color B. As long as traffic is colored A, only counter C(A)R1 will be incremented, while C(B)R1 is not incremented; vice versa, when the traffic is colored as B, only C(B)R1 is incremented. C(A)R1 and C(B)R1 can be used as reference values to determine the packet loss from R1 to any other measurement point down the path. Router R2, similarly, will need two counters on its ingress interface, C(A)R2 and C(B)R2, to count the packets received on that interface and colored with color A and B respectively. When an A block ends, it is possible to compare C(A)R1 and C(A)R2 and calculate the packet loss within the block; similarly, when the successive B block terminates, it is possible to compare C(B)R1 with C(B)R2, and so on for every successive block. OLD The privacy concerns of network measurement are limited because the method only relies on information contained in the header or encapsulation without any release of user data.Although information in the header or encapsulation is metadata that can be used to compromise the privacy of users, the limited marking technique in this document seems unlikely to substantially increase the existing privacy risks from header or encapsulation metadata.It might be theoretically possible to modulate the marking to serve as a covert channel, but it would have a very low data rate if it is to avoid adversely affecting the measurement systems that monitor the marking. NEW The privacy concerns of network measurement are limited because the method only relies on information contained in the header or encapsulation without any release of user data. Although information in the header or encapsulation is metadata that can be used to compromise the privacy of users, the limited marking technique in this document seems unlikely to substantially increase the existing privacy risks from header or encapsulation metadata. It might be theoretically possible to modulate the marking to serve as a covert channel, but it would have a very low data rate if it is to avoid adversely affecting the measurement systems that monitor the marking.
