| < draft-ietf-ippm-capacity-metric-method-11.txt | draft-ietf-ippm-capacity-metric-method-12.txt > | |||
|---|---|---|---|---|
| Network Working Group A. Morton | Network Working Group A. Morton | |||
| Internet-Draft AT&T Labs | Internet-Draft AT&T Labs | |||
| Intended status: Standards Track R. Geib | Intended status: Standards Track R. Geib | |||
| Expires: December 3, 2021 Deutsche Telekom | Expires: December 11, 2021 Deutsche Telekom | |||
| L. Ciavattone | L. Ciavattone | |||
| AT&T Labs | AT&T Labs | |||
| June 1, 2021 | June 9, 2021 | |||
| Metrics and Methods for One-way IP Capacity | Metrics and Methods for One-way IP Capacity | |||
| draft-ietf-ippm-capacity-metric-method-11 | draft-ietf-ippm-capacity-metric-method-12 | |||
| Abstract | Abstract | |||
| This memo revisits the problem of Network Capacity metrics first | This memo revisits the problem of Network Capacity metrics first | |||
| examined in RFC 5136. The memo specifies a more practical Maximum | examined in RFC 5136. The memo specifies a more practical Maximum | |||
| IP-Layer Capacity metric definition catering for measurement | IP-Layer Capacity metric definition catering for measurement | |||
| purposes, and outlines the corresponding methods of measurement. | purposes, and outlines the corresponding methods of measurement. | |||
| Status of This Memo | Status of This Memo | |||
| skipping to change at page 1, line 36 ¶ | skipping to change at page 1, line 36 ¶ | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at https://datatracker.ietf.org/drafts/current/. | Drafts is at https://datatracker.ietf.org/drafts/current/. | |||
| Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| This Internet-Draft will expire on December 3, 2021. | This Internet-Draft will expire on December 11, 2021. | |||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2021 IETF Trust and the persons identified as the | Copyright (c) 2021 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (https://trustee.ietf.org/license-info) in effect on the date of | (https://trustee.ietf.org/license-info) in effect on the date of | |||
| publication of this document. Please review these documents | publication of this document. Please review these documents | |||
| skipping to change at page 2, line 14 ¶ | skipping to change at page 2, line 14 ¶ | |||
| the Trust Legal Provisions and are provided without warranty as | the Trust Legal Provisions and are provided without warranty as | |||
| described in the Simplified BSD License. | described in the Simplified BSD License. | |||
| Table of Contents | Table of Contents | |||
| 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 | |||
| 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 | 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 | |||
| 2. Scope, Goals, and Applicability . . . . . . . . . . . . . . . 4 | 2. Scope, Goals, and Applicability . . . . . . . . . . . . . . . 4 | |||
| 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 5 | 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 5 | |||
| 4. General Parameters and Definitions . . . . . . . . . . . . . 6 | 4. General Parameters and Definitions . . . . . . . . . . . . . 6 | |||
| 5. IP-Layer Capacity Singleton Metric Definitions . . . . . . . 7 | 5. IP-Layer Capacity Singleton Metric Definitions . . . . . . . 8 | |||
| 5.1. Formal Name . . . . . . . . . . . . . . . . . . . . . . . 8 | 5.1. Formal Name . . . . . . . . . . . . . . . . . . . . . . . 8 | |||
| 5.2. Parameters . . . . . . . . . . . . . . . . . . . . . . . 8 | 5.2. Parameters . . . . . . . . . . . . . . . . . . . . . . . 8 | |||
| 5.3. Metric Definitions . . . . . . . . . . . . . . . . . . . 8 | 5.3. Metric Definitions . . . . . . . . . . . . . . . . . . . 8 | |||
| 5.4. Related Round-Trip Delay and One-way Loss Definitions . . 9 | 5.4. Related Round-Trip Delay and One-way Loss Definitions . . 9 | |||
| 5.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . 10 | 5.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . 10 | |||
| 5.6. Reporting the Metric . . . . . . . . . . . . . . . . . . 10 | 5.6. Reporting the Metric . . . . . . . . . . . . . . . . . . 10 | |||
| 6. Maximum IP-Layer Capacity Metric Definitions (Statistic) . . 10 | 6. Maximum IP-Layer Capacity Metric Definitions (Statistic) . . 10 | |||
| 6.1. Formal Name . . . . . . . . . . . . . . . . . . . . . . . 10 | 6.1. Formal Name . . . . . . . . . . . . . . . . . . . . . . . 10 | |||
| 6.2. Parameters . . . . . . . . . . . . . . . . . . . . . . . 10 | 6.2. Parameters . . . . . . . . . . . . . . . . . . . . . . . 11 | |||
| 6.3. Metric Definitions . . . . . . . . . . . . . . . . . . . 11 | 6.3. Metric Definitions . . . . . . . . . . . . . . . . . . . 11 | |||
| 6.4. Related Round-Trip Delay and One-way Loss Definitions . . 12 | 6.4. Related Round-Trip Delay and One-way Loss Definitions . . 13 | |||
| 6.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . 12 | 6.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . 13 | |||
| 6.6. Reporting the Metric . . . . . . . . . . . . . . . . . . 13 | 6.6. Reporting the Metric . . . . . . . . . . . . . . . . . . 13 | |||
| 7. IP-Layer Sender Bit Rate Singleton Metric Definitions . . . . 13 | 7. IP-Layer Sender Bit Rate Singleton Metric Definitions . . . . 14 | |||
| 7.1. Formal Name . . . . . . . . . . . . . . . . . . . . . . . 14 | 7.1. Formal Name . . . . . . . . . . . . . . . . . . . . . . . 14 | |||
| 7.2. Parameters . . . . . . . . . . . . . . . . . . . . . . . 14 | 7.2. Parameters . . . . . . . . . . . . . . . . . . . . . . . 14 | |||
| 7.3. Metric Definition . . . . . . . . . . . . . . . . . . . . 14 | 7.3. Metric Definition . . . . . . . . . . . . . . . . . . . . 15 | |||
| 7.4. Discussion . . . . . . . . . . . . . . . . . . . . . . . 15 | 7.4. Discussion . . . . . . . . . . . . . . . . . . . . . . . 15 | |||
| 7.5. Reporting the Metric . . . . . . . . . . . . . . . . . . 15 | 7.5. Reporting the Metric . . . . . . . . . . . . . . . . . . 15 | |||
| 8. Method of Measurement . . . . . . . . . . . . . . . . . . . . 15 | 8. Method of Measurement . . . . . . . . . . . . . . . . . . . . 15 | |||
| 8.1. Load Rate Adjustment Algorithm . . . . . . . . . . . . . 15 | 8.1. Load Rate Adjustment Algorithm . . . . . . . . . . . . . 16 | |||
| 8.2. Measurement Qualification or Verification . . . . . . . . 20 | 8.2. Measurement Qualification or Verification . . . . . . . . 21 | |||
| 8.3. Measurement Considerations . . . . . . . . . . . . . . . 22 | 8.3. Measurement Considerations . . . . . . . . . . . . . . . 22 | |||
| 8.4. Running Code . . . . . . . . . . . . . . . . . . . . . . 24 | 8.4. Running Code . . . . . . . . . . . . . . . . . . . . . . 24 | |||
| 9. Reporting Formats . . . . . . . . . . . . . . . . . . . . . . 24 | 9. Reporting Formats . . . . . . . . . . . . . . . . . . . . . . 25 | |||
| 9.1. Configuration and Reporting Data Formats . . . . . . . . 26 | 9.1. Configuration and Reporting Data Formats . . . . . . . . 27 | |||
| 10. Security Considerations . . . . . . . . . . . . . . . . . . . 26 | 10. Security Considerations . . . . . . . . . . . . . . . . . . . 27 | |||
| 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27 | 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28 | |||
| 12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 28 | 12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 28 | |||
| 13. Appendix A - Load Rate Adjustment Pseudo Code . . . . . . . . 28 | 13. Appendix A - Load Rate Adjustment Pseudo Code . . . . . . . . 28 | |||
| 14. Appendix B - RFC 8085 UDP Guidelines Check . . . . . . . . . 29 | 14. Appendix B - RFC 8085 UDP Guidelines Check . . . . . . . . . 29 | |||
| 14.1. Assessment of Mandatory Requirements . . . . . . . . . . 29 | 14.1. Assessment of Mandatory Requirements . . . . . . . . . . 29 | |||
| 14.2. Assessment of Recommendations . . . . . . . . . . . . . 31 | 14.2. Assessment of Recommendations . . . . . . . . . . . . . 31 | |||
| 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 34 | 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 34 | |||
| 15.1. Normative References . . . . . . . . . . . . . . . . . . 34 | 15.1. Normative References . . . . . . . . . . . . . . . . . . 34 | |||
| 15.2. Informative References . . . . . . . . . . . . . . . . . 35 | 15.2. Informative References . . . . . . . . . . . . . . . . . 35 | |||
| Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37 | Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37 | |||
| skipping to change at page 6, line 25 ¶ | skipping to change at page 6, line 25 ¶ | |||
| 4. Content and applications are moving physically closer to users. | 4. Content and applications are moving physically closer to users. | |||
| 5. There is less emphasis on ISP gateway measurements, possibly due | 5. There is less emphasis on ISP gateway measurements, possibly due | |||
| to less traffic crossing ISP gateways in the future. | to less traffic crossing ISP gateways in the future. | |||
| 4. General Parameters and Definitions | 4. General Parameters and Definitions | |||
| This section lists the REQUIRED input factors to specify a Sender or | This section lists the REQUIRED input factors to specify a Sender or | |||
| Receiver metric. | Receiver metric. | |||
| o Src, the address of a host (such as the globally routable IP | o Src, one of the addresses of a host (such as a globally routable | |||
| address). | IP address). | |||
| o Dst, the address of a host (such as the globally routable IP | o Dst, one of the addresses of a host (such as a globally routable | |||
| address). | IP address). | |||
| o MaxHops, the limit on the number of Hops a specific packet may | o MaxHops, the limit on the number of Hops a specific packet may | |||
| visit as it traverses from the host at Src to the host at Dst | visit as it traverses from the host at Src to the host at Dst | |||
| (implemented in the TTL or Hop Limit). | (implemented in the TTL or Hop Limit). | |||
| o T0, the time at the start of measurement interval, when packets | o T0, the time at the start of measurement interval, when packets | |||
| are first transmitted from the Source. | are first transmitted from the Source. | |||
| o I, the nominal duration of a measurement interval at the | o I, the nominal duration of a measurement interval at the | |||
| destination (default 10 sec) | destination (default 10 sec) | |||
| skipping to change at page 7, line 16 ¶ | skipping to change at page 7, line 16 ¶ | |||
| destination, set sufficiently long to disambiguate packets with | destination, set sufficiently long to disambiguate packets with | |||
| long delays from packets that are discarded (lost), such that the | long delays from packets that are discarded (lost), such that the | |||
| distribution of one-way delay is not truncated. | distribution of one-way delay is not truncated. | |||
| o F, the number of different flows synthesized by the method | o F, the number of different flows synthesized by the method | |||
| (default 1 flow) | (default 1 flow) | |||
| o flow, the stream of packets with the same n-tuple of designated | o flow, the stream of packets with the same n-tuple of designated | |||
| header fields that (when held constant) result in identical | header fields that (when held constant) result in identical | |||
| treatment in a multi-path decision (such as the decision taken in | treatment in a multi-path decision (such as the decision taken in | |||
| load balancing). Note: The IPv6 flow label MAY be included in the | load balancing). Note: The IPv6 flow label SHOULD be included in | |||
| flow definition when routers have complied with [RFC6438] | the flow definition when routers have complied with [RFC6438] | |||
| guidelines. | guidelines. | |||
| o Type-P, the complete description of the test packets for which | o Type-P, the complete description of the test packets for which | |||
| this assessment applies (including the flow-defining fields). | this assessment applies (including the flow-defining fields). | |||
| Note that the UDP transport layer is one requirement for test | Note that the UDP transport layer is one requirement for test | |||
| packets specified below. Type-P is a parallel concept to | packets specified below. Type-P is a parallel concept to | |||
| "population of interest" defined in clause 6.1.1 of[Y.1540]. | "population of interest" defined in clause 6.1.1 of[Y.1540]. | |||
| o Payload Content, this IPPM Framework-conforming metric and method | ||||
| includes packet payload content as an aspect of the Type-P | ||||
| parameter, which can help to improve measurement determinism. If | ||||
| there is payload compression in the path and tests intend to | ||||
| characterize a possible advantage due to compression, then payload | ||||
| content SHOULD be supplied by a pseudo-random sequence generator, | ||||
| by using part of a compressed file, or by other means. See | ||||
| Section 3.1.2 of [RFC7312]. | ||||
| o PM, a list of fundamental metrics, such as loss, delay, and | o PM, a list of fundamental metrics, such as loss, delay, and | |||
| reordering, and corresponding target performance threshold. At | reordering, and corresponding target performance threshold. At | |||
| least one fundamental metric and target performance threshold MUST | least one fundamental metric and target performance threshold MUST | |||
| be supplied (such as One-way IP Packet Loss [RFC7680] equal to | be supplied (such as One-way IP Packet Loss [RFC7680] equal to | |||
| zero). | zero). | |||
| A non-Parameter which is required for several metrics is defined | A non-Parameter which is required for several metrics is defined | |||
| below: | below: | |||
| o T, the host time of the *first* test packet's *arrival* as | o T, the host time of the *first* test packet's *arrival* as | |||
| skipping to change at page 16, line 11 ¶ | skipping to change at page 16, line 32 ¶ | |||
| offered load rates that will be supported (R1 through Rn, in | offered load rates that will be supported (R1 through Rn, in | |||
| ascending order, corresponding to indexed rows in the table). It is | ascending order, corresponding to indexed rows in the table). It is | |||
| RECOMMENDED that rates begin with 0.5 Mbps at index zero, use 1 Mbps | RECOMMENDED that rates begin with 0.5 Mbps at index zero, use 1 Mbps | |||
| at index one, and then continue in 1 Mbps increments to 1 Gbps. | at index one, and then continue in 1 Mbps increments to 1 Gbps. | |||
| Above 1 Gbps, and up to 10 Gbps, it is RECOMMENDED that 100 Mbps | Above 1 Gbps, and up to 10 Gbps, it is RECOMMENDED that 100 Mbps | |||
| increments be used. Above 10 Gbps, increments of 1 Gbps are | increments be used. Above 10 Gbps, increments of 1 Gbps are | |||
| RECOMMENDED. A higher initial IP-Layer Sender Bitrate might be | RECOMMENDED. A higher initial IP-Layer Sender Bitrate might be | |||
| configured when the test operator is certain that the Maximum IP- | configured when the test operator is certain that the Maximum IP- | |||
| Layer Capacity is well-above the initial IP-Layer Sender Bitrate and | Layer Capacity is well-above the initial IP-Layer Sender Bitrate and | |||
| factors such as test duration and total test traffic play an | factors such as test duration and total test traffic play an | |||
| important role. | important role. The sending rate table SHOULD backet the maximum | |||
| capacity where it will make measurements, including constrained rates | ||||
| less than 500kbps if applicable. | ||||
| Each rate is defined as datagrams of size ss, sent as a burst of | Each rate is defined as datagrams of size ss, sent as a burst of | |||
| count cc, each time interval tt (default for tt is 1ms, a likely | count cc, each time interval tt (default for tt is 1ms, a likely | |||
| system tick-interval). While it is advantageous to use datagrams of | system tick-interval). While it is advantageous to use datagrams of | |||
| as large a size as possible, it may be prudent to use a slightly | as large a size as possible, it may be prudent to use a slightly | |||
| smaller maximum that allows for secondary protocol headers and/or | smaller maximum that allows for secondary protocol headers and/or | |||
| tunneling without resulting in IP-Layer fragmentation. Selection of | tunneling without resulting in IP-Layer fragmentation. Selection of | |||
| a new rate is indicated by a calculation on the current row, Rx. For | a new rate is indicated by a calculation on the current row, Rx. For | |||
| example: | example: | |||
| skipping to change at page 17, line 46 ¶ | skipping to change at page 18, line 20 ¶ | |||
| further feedback sent. | further feedback sent. | |||
| feedback message timeout Operation: The feedback message timeout | feedback message timeout Operation: The feedback message timeout | |||
| SHALL be reset to the configured value each time a feedback | SHALL be reset to the configured value each time a feedback | |||
| message is received. If the timeout expires, the sender SHALL be | message is received. If the timeout expires, the sender SHALL be | |||
| closed and no further load packets sent. | closed and no further load packets sent. | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | Parameter | Default | Tested Range | Expected Safe Range | | | Parameter | Default | Tested Range | Expected Safe Range | | |||
| | | | or values | (not entirely tested, | | | | | or values | (not entirely tested, | | |||
| | | | | other values NOT | | | | | | other | | |||
| | | | | values NOT | | ||||
| | | | | RECOMMENDED) | | | | | | RECOMMENDED) | | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | FT, | 50ms | 20ms, 50ms, | 20ms <= FT <= 250ms | | | FT, | 50ms | 20ms, 50ms, | 20ms <= FT <= 250ms | | |||
| | feedback | | 100ms | Larger values may | | | feedback | | 100ms | Larger values may | | |||
| | time | | | slow the rate | | | time | | | slow the rate | | |||
| | interval | | | increase and fail to | | | interval | | | increase and fail to | | |||
| | | | | find the max | | | | | | find the max | | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | Feedback | L*FT, L=20 | L=100 with | 0.5sec <= L*FT <= | | | Feedback | L*FT, L=20 | L=100 with | 0.5sec <= L*FT <= | | |||
| | message | (1sec with | FT=50ms | 30sec Upper limit for | | | message | (1sec with | FT=50ms | 30sec Upper limit for | | |||
| | timeout | FT=50ms) | (5sec) | very unreliable test | | | timeout | FT=50ms) | (5sec) | very unreliable | | |||
| | (stop test) | | | paths only | | | (stop test) | | | test paths only | | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | load packet | 1sec | 5sec | 0.250sec - 30sec | | | load packet | 1sec | 5sec | 0.250sec - 30sec | | |||
| | timeout | | | Upper limit for very | | | timeout | | | Upper limit for very | | |||
| | (stop test) | | | unreliable test paths | | | (stop test) | | | unreliable test paths | | |||
| | | | | only | | | | | | only | | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | table index | 0.5Mbps | 0.5Mbps | when testing <=10Gbps | | | table index | 0.5Mbps | 0.5Mbps | when testing <=10Gbps | | |||
| | 0 | | | | | | 0 | | | | | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | table index | 1Mbps | 1Mbps | when testing <=10Gbps | | | table index | 1Mbps | 1Mbps | when testing <=10Gbps | | |||
| skipping to change at page 18, line 39 ¶ | skipping to change at page 19, line 14 ¶ | |||
| | rate>1Gbps | | | | | | rate>1Gbps | | | | | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | table index | 1Gbps | untested | >10Gbps | | | table index | 1Gbps | untested | >10Gbps | | |||
| | (step) | | | | | | (step) | | | | | |||
| | size, | | | | | | size, | | | | | |||
| | rate>10Gbps | | | | | | rate>10Gbps | | | | | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | ss, UDP | none | <=1222 | Recommend max at | | | ss, UDP | none | <=1222 | Recommend max at | | |||
| | payload | | | largest value that | | | payload | | | largest value that | | |||
| | size, bytes | | | avoids fragmentation; | | | size, bytes | | | avoids fragmentation; | | |||
| | | | | use of too-small | | | | | | use of too- | | |||
| | | | | payload size might | | | | | | small payload size | | |||
| | | | | result in unexpected | | | | | | might result in | | |||
| | | | | sender limitations. | | | | | | unexpected sender | | |||
| | | | | limitations. | | ||||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | cc, burst | none | 1<=cc<= 100 | same as tested. Vary | | | cc, burst | none | 1<=cc<= 100 | same as tested. Vary | | |||
| | count | | | cc as needed to | | | count | | | cc as needed to | | |||
| | | | | create the desired | | | | | | create the desired | | |||
| | | | | maximum sending rate. | | | | | | maximum | | |||
| | | | | Sender buffer size | | | | | | sending rate. Sender | | |||
| | | | | may limit cc in | | | | | | buffer size may limit | | |||
| | | | | implementation. | | | | | | cc in implementation. | | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | tt, burst | 100microsec | 100microsec, | available range of | | | tt, burst | 100microsec | 100microsec, | available range of | | |||
| | interval | | 1msec | "tick" values (HZ | | | interval | | 1msec | "tick" values (HZ | | |||
| | | | | param) | | | | | | param) | | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | low delay | 30ms | 5ms, 30ms | same as tested | | | low delay | 30ms | 5ms, 30ms | same as tested | | |||
| | range | | | | | | range | | | | | |||
| | threshold | | | | | | threshold | | | | | |||
| +-------------+-------------+---------------+-----------------------+ | +-------------+-------------+---------------+-----------------------+ | |||
| | high delay | 90ms | 10ms, 90ms | same as tested | | | high delay | 90ms | 10ms, 90ms | same as tested | | |||
| skipping to change at page 24, line 6 ¶ | skipping to change at page 24, line 23 ¶ | |||
| aggregate. | aggregate. | |||
| 3. Internet access policies may limit the IP-Layer Capacity | 3. Internet access policies may limit the IP-Layer Capacity | |||
| depending on the Type-P of packets, possibly reserving capacity | depending on the Type-P of packets, possibly reserving capacity | |||
| for various stream types. | for various stream types. | |||
| Each flow would be controlled using its own implementation of the | Each flow would be controlled using its own implementation of the | |||
| load rate adjustment (search) algorithm. | load rate adjustment (search) algorithm. | |||
| It is obviously counter-productive to run more than one independent | It is obviously counter-productive to run more than one independent | |||
| test (regardless of the number of flows in the test stream) | and concurrent test (regardless of the number of flows in the test | |||
| attempting to measure the *maximum* capacity between the same Source | stream) attempting to measure the *maximum* capacity on a single | |||
| and Destination. The number of concurrent, independent tests between | path. The number of concurrent, independent tests of a path SHALL be | |||
| the same Source and Destination SHALL be limited to one. | limited to one. | |||
| Tests of a v4-v6 transition mechanism might well be the intended | ||||
| subject of a capacity test. As long as the IPv4 and IPv6 packets | ||||
| sent/received are both standard-formed, this should be allowed (and | ||||
| the change in header size easily accounted for on a per-packet | ||||
| basis). | ||||
| As testing continues, implementers should expect some evolution in | As testing continues, implementers should expect some evolution in | |||
| the methods. The ITU-T has published a Supplement (60) to the | the methods. The ITU-T has published a Supplement (60) to the | |||
| Y-series of Recommendations, "Interpreting ITU-T Y.1540 Maximum IP- | Y-series of Recommendations, "Interpreting ITU-T Y.1540 Maximum IP- | |||
| Layer Capacity measurements", [Y.Sup60], which is the result of | Layer Capacity measurements", [Y.Sup60], which is the result of | |||
| continued testing with the metric, and those results have improved | continued testing with the metric, and those results have improved | |||
| the method described here. | the method described here. | |||
| 8.4. Running Code | 8.4. Running Code | |||
| End of changes. 21 change blocks. | ||||
| 38 lines changed or deleted | 57 lines changed or added | |||
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