< draft-ietf-lsr-flex-algo-bw-con-01.txt   draft-ietf-lsr-flex-algo-bw-con-02.txt >
SPRING S. Hegde SPRING S. Hegde
Internet-Draft W. Britto Internet-Draft W. Britto
Intended status: Standards Track R. Shetty Intended status: Standards Track R. Shetty
Expires: January 13, 2022 Juniper Networks Inc. Expires: 24 September 2022 Juniper Networks Inc.
B. Decraene B. Decraene
Orange Orange
P. Psenak P. Psenak
Cisco Systems Cisco Systems
T. Li T. Li
Arista Networks Arista Networks
July 12, 2021 23 March 2022
Flexible Algorithms: Bandwidth, Delay, Metrics and Constraints Flexible Algorithms: Bandwidth, Delay, Metrics and Constraints
draft-ietf-lsr-flex-algo-bw-con-01 draft-ietf-lsr-flex-algo-bw-con-02
Abstract Abstract
Many networks configure the link metric relative to the link Many networks configure the link metric relative to the link
capacity. High bandwidth traffic gets routed as per the link capacity. High bandwidth traffic gets routed as per the link
capacity. Flexible algorithms provides mechanisms to create capacity. Flexible algorithms provides mechanisms to create
constraint based paths in IGP. This draft documents a generic metric constraint based paths in IGP. This draft documents a generic metric
type and set of bandwidth related constraints to be used in Flexible type and set of bandwidth related constraints to be used in Flexible
Algorithms. Algorithms.
skipping to change at page 1, line 48 skipping to change at page 1, line 48
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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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 January 13, 2022. This Internet-Draft will expire on 24 September 2022.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Generic Metric Advertisement . . . . . . . . . . . . . . . . 4 2. Generic Metric Advertisement . . . . . . . . . . . . . . . . 4
2.1. ISIS Generic Metric sub-TLV . . . . . . . . . . . . . . . 5 2.1. ISIS Generic Metric sub-TLV . . . . . . . . . . . . . . . 5
2.2. OSPF Generic Metric sub-TLV . . . . . . . . . . . . . . . 6 2.2. OSPF Generic Metric sub-TLV . . . . . . . . . . . . . . . 6
2.3. Generic Metric applicability to Flexible Algorithms 2.3. Generic Metric applicability to Flexible Algorithms
Multi-domain/Multi-area networks . . . . . . . . . . . . 7 Multi-domain/Multi-area networks . . . . . . . . . . . . 7
3. FAD constraint sub-TLVs . . . . . . . . . . . . . . . . . . . 7 3. FAD constraint sub-TLVs . . . . . . . . . . . . . . . . . . . 7
3.1. ISIS FAD constraint sub-TLVs . . . . . . . . . . . . . . 8 3.1. ISIS FAD constraint sub-TLVs . . . . . . . . . . . . . . 8
3.1.1. ISIS Exclude Minimum Bandwidth sub-TLV . . . . . . . 8 3.1.1. ISIS Exclude Minimum Bandwidth sub-TLV . . . . . . . 8
3.1.2. ISIS Exclude Maximum Delay sub-TLV . . . . . . . . . 8 3.1.2. ISIS Exclude Maximum Delay sub-TLV . . . . . . . . . 9
3.2. OSPF FAD constraint sub-TLVs . . . . . . . . . . . . . . 9 3.2. OSPF FAD constraint sub-TLVs . . . . . . . . . . . . . . 10
3.2.1. OSPF Exclude Minimum Bandwidth sub-TLV . . . . . . . 9 3.2.1. OSPF Exclude Minimum Bandwidth sub-TLV . . . . . . . 10
3.2.2. OSPF Exclude Maximum Delay sub-TLV . . . . . . . . . 10 3.2.2. OSPF Exclude Maximum Delay sub-TLV . . . . . . . . . 11
4. Bandwidth Metric Advertisement . . . . . . . . . . . . . . . 11 4. Bandwidth Metric Advertisement . . . . . . . . . . . . . . . 11
4.1. Automatic Metric Calculation . . . . . . . . . . . . . . 12 4.1. Automatic Metric Calculation . . . . . . . . . . . . . . 12
4.1.1. Automatic Metric Calculation Modes . . . . . . . . . 12 4.1.1. Automatic Metric Calculation Modes . . . . . . . . . 12
4.1.2. Automatic Metric Calculation Methods . . . . . . . . 13 4.1.2. Automatic Metric Calculation Methods . . . . . . . . 13
4.1.3. ISIS FAD constraint sub-TLVs for automatic metric 4.1.3. ISIS FAD constraint sub-TLVs for automatic metric
calculation . . . . . . . . . . . . . . . . . . . . . 14 calculation . . . . . . . . . . . . . . . . . . . . . 14
4.1.4. OSPF FAD constraint sub-TLVs for automatic metric 4.1.4. OSPF FAD constraint sub-TLVs for automatic metric
calculation . . . . . . . . . . . . . . . . . . . . . 18 calculation . . . . . . . . . . . . . . . . . . . . . 18
5. Bandwidth metric considerations . . . . . . . . . . . . . . . 22 5. Bandwidth metric considerations . . . . . . . . . . . . . . . 22
6. Calculation of Flex-Algorithm paths . . . . . . . . . . . . . 22 6. Calculation of Flex-Algorithm paths . . . . . . . . . . . . . 23
7. Backward Compatibility . . . . . . . . . . . . . . . . . . . 23 7. Backward Compatibility . . . . . . . . . . . . . . . . . . . 23
8. Security Considerations . . . . . . . . . . . . . . . . . . . 23 8. Security Considerations . . . . . . . . . . . . . . . . . . . 23
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
9.1. IGP Metric-Type Registry . . . . . . . . . . . . . . . . 23 9.1. IGP Metric-Type Registry . . . . . . . . . . . . . . . . 23
9.2. ISIS Sub-Sub-TLVs for Flexible Algorithm Definition Sub- 9.2. ISIS Sub-Sub-TLVs for Flexible Algorithm Definition
TLV . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Sub-TLV . . . . . . . . . . . . . . . . . . . . . . . . . 23
9.3. OSPF Sub-TLVs for Flexible Algorithm Definition Sub-TLV . 24 9.3. OSPF Sub-TLVs for Flexible Algorithm Definition
Sub-TLV . . . . . . . . . . . . . . . . . . . . . . . . . 24
9.4. Sub-TLVs for TLVs 22, 23, 25, 141, 222, and 223 . . . . . 24 9.4. Sub-TLVs for TLVs 22, 23, 25, 141, 222, and 223 . . . . . 24
9.5. OSPFv2 Extended Link TLV Sub-TLVs . . . . . . . . . . . . 24 9.5. OSPFv2 Extended Link TLV Sub-TLVs . . . . . . . . . . . . 25
9.6. Types for sub-TLVs of TE Link TLV (Value 2) . . . . . . . 25 9.6. Types for sub-TLVs of TE Link TLV (Value 2) . . . . . . . 25
9.7. OSPFv3 Extended-LSA Sub-TLVs . . . . . . . . . . . . . . 25 9.7. OSPFv3 Extended-LSA Sub-TLVs . . . . . . . . . . . . . . 25
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 25 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 25
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 25 11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 25
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 25 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 25
12.1. Normative References . . . . . . . . . . . . . . . . . . 25 12.1. Normative References . . . . . . . . . . . . . . . . . . 25
12.2. Informative References . . . . . . . . . . . . . . . . . 26 12.2. Informative References . . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27
1. Introduction 1. Introduction
High bandwidth traffic such as residential internet traffic and High bandwidth traffic such as residential internet traffic and
machine to machine elephant flows benefit from using high capacity machine to machine elephant flows benefit from using high capacity
links. Accordingly, many network operators define a link's metric links. Accordingly, many network operators define a link's metric
relative to its capacity to help direct traffic to higher bandwidth relative to its capacity to help direct traffic to higher bandwidth
links, but this is no guarantee that lower bandwidth links will be links, but this is no guarantee that lower bandwidth links will be
avoided, especially in failure scenarios. To ensure that elephant avoided, especially in failure scenarios. To ensure that elephant
flows are only placed on high capacity links, it would be useful to flows are only placed on high capacity links, it would be useful to
skipping to change at page 6, line 39 skipping to change at page 6, line 39
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value | | Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type : TBD (To be assigned by IANA) Type : TBD (To be assigned by IANA)
Length: 8 octets Length: 8 octets
metric-type = A value from the IGP metric type registry metric-type = A value from the IGP metric type registry
Value : metric value (1- 4,294,967,295) Value : metric value (1- 4,294,967,295)
Figure 2: OSPF Generic Metric sub-TLV Figure 2: OSPF Generic Metric sub-TLV
The Generic Metric sub-TLV MAY be advertised multiple times. For a The Generic Metric sub-TLV MAY be advertised multiple times. For a
particular metric type, the Genreric Metric sub-TLV MUST be particular metric type, the Genreric Metric sub-TLV MUST be
advertised only once for a link when advertised in OSPF Link TLV of advertised only once for a link when advertised in OSPF Link TLV of
Extended Link LSA, Link TLV of TE LSA and sub-TLV of the Router-Link Extended Link LSA, Link TLV of TE LSA and sub-TLV of the Router-Link
TLV in the E-Router-LSA Router-Link TLV in OSPFv3. If there are TLV in the E-Router-LSA Router-Link TLV in OSPFv3. If there are
multiple Genreric Metric sub-TLVs advertised for a link for the same multiple Genreric Metric sub-TLVs advertised for a link for the same
metric type in a received LSA, the first one MUST be used and the metric type in a received LSA, the first one MUST be used and the
subsequent ones MUST be ignored.If the metric type indicates a subsequent ones MUST be ignored.If the metric type indicates a
standard metric type for which there are other advertisement standard metric type for which there are other advertisement
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| max link delay | | max link delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: where:
Type: TBD Type: TBD
Length: 3 octets Length: 3 octets
Max link delay: Maximum link delay in microseconds Max link delay: Maximum link delay in microseconds
Figure 4: ISIS FAEMD sub-TLV Figure 4: ISIS FAEMD sub-TLV
The FAEMD sub-TLV MUST appear only once in the FAD sub-TLV. If it The FAEMD sub-TLV MUST appear only once in the FAD sub-TLV. If it
appears more than once, the ISIS FAD Sub-TLV MUST be ignored by the appears more than once, the ISIS FAD Sub-TLV MUST be ignored by the
receiver. receiver.
The Maximum link delay advertised in FAEMD sub-TLV MUST be compared The Maximum link delay advertised in FAEMD sub-TLV MUST be compared
with Min Unidirectional Link Delay advertised in sub-sub-TLV 34 of with Min Unidirectional Link Delay advertised in sub-sub-TLV 34 of
ASLA sub-TLV [RFC 8919]. If L-Flag is set in the ASLA sub-TLV, the ASLA sub-TLV [RFC 8919]. If L-Flag is set in the ASLA sub-TLV, the
Maximum link delay advertised in FAEMD sub-TLV MUST be compared with Maximum link delay advertised in FAEMD sub-TLV MUST be compared with
Min Unidirectional Link Delay as advertised by the sub-TLV 34 of the Min Unidirectional Link Delay as advertised by the sub-TLV 34 of the
skipping to change at page 10, line 21 skipping to change at page 10, line 35
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: where:
Type: TBD Type: TBD
Length: 4 octets. Length: 4 octets.
Min Bandwidth: link bandwidth is encoded in 32 bits in IEEE Min Bandwidth: link bandwidth is encoded in 32 bits in IEEE
floating point format. The units are bytes per second. floating point format. The units are bytes per second.
Figure 5: OSPF FAEMB sub-TLV Figure 5: OSPF FAEMB sub-TLV
The FAEMB sub-TLV MUST appear only once in the FAD sub-TLV. If it The FAEMB sub-TLV MUST appear only once in the FAD sub-TLV. If it
appears more than once, the OSPF FAD TLV MUST be ignored by the appears more than once, the OSPF FAD TLV MUST be ignored by the
receiver. The Maximum Link Bandwidth as advertised in Extended Link receiver. The Maximum Link Bandwidth as advertised in Extended Link
TLV in the Extended Link Opaque LSA in OSPFv2 [RFC7684] or as a sub- TLV in the Extended Link Opaque LSA in OSPFv2 [RFC7684] or as a sub-
TLV of the Router-Link TLV in the E-Router-LSA Router-Link TLV in TLV of the Router-Link TLV in the E-Router-LSA Router-Link TLV in
OSPFv3 [RFC8362] MUST be compared against the Minimum bandwidth OSPFv3 [RFC8362] MUST be compared against the Minimum bandwidth
advertised in FAEMB sub-TLV. If the link bandwidth is lower than the advertised in FAEMB sub-TLV. If the link bandwidth is lower than the
Minimum bandwidth advertised in FAEMB sub-TLV, the link MUST be Minimum bandwidth advertised in FAEMB sub-TLV, the link MUST be
excluded from the Flex-Algorithm topology. If a link does not have excluded from the Flex-Algorithm topology. If a link does not have
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| Max Delay | | Max Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: where:
Type: TBD Type: TBD
Length: 3 octets Length: 3 octets
Max link delay: Maximum link delay in microseconds Max link delay: Maximum link delay in microseconds
Figure 6: OSPF FAEMD sub-TLV Figure 6: OSPF FAEMD sub-TLV
The FAEMD sub-TLV MUST appear only once in the OSPF FAD TLV. If it The FAEMD sub-TLV MUST appear only once in the OSPF FAD TLV. If it
appears more than once, the OSPF FAD TLV MUST be ignored by the appears more than once, the OSPF FAD TLV MUST be ignored by the
receiver. The Min Unidirectional Link Delay as advertised by sub- receiver. The Min Unidirectional Link Delay as advertised by sub-
sub-TLV 12 of ASLA sub-TLV [RFC 8920], MUST be compared against the sub-TLV 12 of ASLA sub-TLV [RFC 8920], MUST be compared against the
Maximum delay advertised in FAEMD sub-TLV. If the Min Unidirectional Maximum delay advertised in FAEMD sub-TLV. If the Min Unidirectional
Link Delay is higher than the Maximum delay advertised in FAEMD sub- Link Delay is higher than the Maximum delay advertised in FAEMD sub-
TLV, the link MUST be excluded from the Flex-Algorithm topology If a TLV, the link MUST be excluded from the Flex-Algorithm topology If a
link does not have the Min Unidirectional Link Delay advertised but link does not have the Min Unidirectional Link Delay advertised but
the FAD contains this sub-TLV, then then that link MUST NOT be the FAD contains this sub-TLV, then then that link MUST NOT be
skipping to change at page 15, line 38 skipping to change at page 15, line 38
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|G| | | | |G| | | |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
G-flag: when set, interface group Mode MUST be used to derive total link bandwidth. G-flag: when set, interface group Mode MUST be used to derive total link bandwidth.
Metric calculation: (Reference_bandwidth) / Metric calculation: (Reference_bandwidth) /
(Total_link_bandwidth - (Total_link_bandwidth -
(Modulus of(Total_link_bandwidth,granularity_bw))) (Modulus of(Total_link_bandwidth,granularity_bw)))
Figure 8: ISIS FADRB sub-TLV Figure 8: ISIS FADRB sub-TLV
Granularity Bandwidth value ensures that the metric does not change Granularity Bandwidth value ensures that the metric does not change
when there is a small change in the link bandwidth. The ISIS FADRB when there is a small change in the link bandwidth. The ISIS FADRB
Sub-TLV MUST NOT appear more than once in an ISIS FAD sub-TLV. If it Sub-TLV MUST NOT appear more than once in an ISIS FAD sub-TLV. If it
appears more than once, the ISIS FAD sub-TLV MUST be ignored by the appears more than once, the ISIS FAD sub-TLV MUST be ignored by the
receiver. If a Generic Metric sub-TLV with Bandwidth metric type is receiver. If a Generic Metric sub-TLV with Bandwidth metric type is
advertised for a link, the Flex-Algorithm calculation MUST use the advertised for a link, the Flex-Algorithm calculation MUST use the
advertised Bandwidth Metric, and MUST NOT use the automatically advertised Bandwidth Metric, and MUST NOT use the automatically
derived metric for that link. derived metric for that link.
skipping to change at page 17, line 14 skipping to change at page 17, line 12
G-flag: when set, interface group Mode MUST be used to derive total link bandwidth. G-flag: when set, interface group Mode MUST be used to derive total link bandwidth.
Staircase bandwidth threshold and associated metric values. Staircase bandwidth threshold and associated metric values.
Bandwidth Threshold 1: Minimum Link Bandwidth is encoded in 32 bits in IEEE Bandwidth Threshold 1: Minimum Link Bandwidth is encoded in 32 bits in IEEE
floating point format. The units are bytes per second. floating point format. The units are bytes per second.
Bandwidth Threshold 2: Maximum Link Bandwidth is encoded in 32 bits in IEEE Bandwidth Threshold 2: Maximum Link Bandwidth is encoded in 32 bits in IEEE
floating point format. The units are bytes per second. floating point format. The units are bytes per second.
Threshold Metric 1 : metric value range (1 - 4,261,412,864) Threshold Metric 1 : metric value range (1 - 4,261,412,864)
Figure 9: ISIS FADBT sub-TLV Figure 9: ISIS FADBT sub-TLV
When G-flag is set, the cumulative bandwidth of the parallel links is When G-flag is set, the cumulative bandwidth of the parallel links is
computed as described in section Section 4.1.1.2. If G-flag is not computed as described in section Section 4.1.1.2. If G-flag is not
set, the advertised Maximum Link Bandwidth is used. set, the advertised Maximum Link Bandwidth is used.
When the computed link bandwidth is less than Bandwidth Threshold 1, When the computed link bandwidth is less than Bandwidth Threshold 1,
the MAX_METRIC value of 4,261,412,864 MUST be assigned as the the MAX_METRIC value of 4,261,412,864 MUST be assigned as the
Bandwidth Metric on the link during Flex-Algorithm SPF calculation. Bandwidth Metric on the link during Flex-Algorithm SPF calculation.
When the computed link bandwidth is greater than or equal to When the computed link bandwidth is greater than or equal to
skipping to change at page 19, line 41 skipping to change at page 19, line 41
|G| | | | |G| | | |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
G-flag: when set, interface group Mode MUST be used G-flag: when set, interface group Mode MUST be used
to derive total link bandwidth. to derive total link bandwidth.
Metric calculation: (Reference_bandwidth) / Metric calculation: (Reference_bandwidth) /
(Total_link_bandwidth - (Total_link_bandwidth -
(Modulus of(Total_link_bandwidth, Granularity_bw))) (Modulus of(Total_link_bandwidth, Granularity_bw)))
Figure 10: OSPF FADRB sub-TLV Figure 10: OSPF FADRB sub-TLV
Granularity Bandwidth value is used to ensure that the metric does Granularity Bandwidth value is used to ensure that the metric does
not change when there is a small change in the link bandwidth. The not change when there is a small change in the link bandwidth. The
OSPF FADRB Sub-TLV MUST NOT appear more than once in an OSPF FAD TLV. OSPF FADRB Sub-TLV MUST NOT appear more than once in an OSPF FAD TLV.
If it appears more than once, the OSPF FAD TLV MUST be ignored by the If it appears more than once, the OSPF FAD TLV MUST be ignored by the
receiver. If a Generic Metric sub-TLV with Bandwidth metric type is receiver. If a Generic Metric sub-TLV with Bandwidth metric type is
advertised for a link, the Flex-Algorithm calculation MUST use the advertised for a link, the Flex-Algorithm calculation MUST use the
advertised Bandwidth Metric on the link, and MUST NOT use the advertised Bandwidth Metric on the link, and MUST NOT use the
automatically derived metric for that link. automatically derived metric for that link.
skipping to change at page 20, line 45 skipping to change at page 21, line 4
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Threshold Metric n | | Threshold Metric n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: where:
Type: TBD Type: TBD
Length: 2 + n*8 octets. Here n is equal to number of Length: 2 + n*8 octets. Here n is equal to number of
Threshold Metrics specified. Threshold Metrics specified.
n MUST be greater than or equal to 1. n MUST be greater than or equal to 1.
Flags: Flags:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|G| | | | |G| | | |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
G-flag: when set, interface group Mode MUST be used to derive total link bandwidth. G-flag: when set, interface group Mode MUST be used to derive total link bandwidth.
Staircase bandwidth threshold and associated metric values. Staircase bandwidth threshold and associated metric values.
Bandwidth Threshold 1: Minimum Link Bandwidth is encoded in 32 bits in IEEE Bandwidth Threshold 1: Minimum Link Bandwidth is encoded in 32 bits in IEEE
floating point format. The units are bytes per second. floating point format. The units are bytes per second.
Bandwidth Threshold 2: Maximum Link Bandwidth is encoded in 32 bits in IEEE Bandwidth Threshold 2: Maximum Link Bandwidth is encoded in 32 bits in IEEE
floating point format. The units are bytes per second. floating point format. The units are bytes per second.
Threshold Metric 1 : metric value range (1 - 4,294,967,296) Threshold Metric 1 : metric value range (1 - 4,294,967,296)
Figure 11: OSPF FADBT sub-TLV Figure 11: OSPF FADBT sub-TLV
When G-flag is set, the cumulative bandwidth of the parallel links is When G-flag is set, the cumulative bandwidth of the parallel links is
computed as described in section Section 4.1.1.2. If G-flag is not computed as described in section Section 4.1.1.2. If G-flag is not
set, the advertised Maximum Link Bandwidth is used. set, the advertised Maximum Link Bandwidth is used.
When the computed link bandwidth is less than Bandwidth Threshold 1 , When the computed link bandwidth is less than Bandwidth Threshold 1 ,
the MAX_METRIC value of 4,294,967,296 MUST be assigned as the the MAX_METRIC value of 4,294,967,296 MUST be assigned as the
Bandwidth Metric on the link during Flex-Algorithm SPF calculation. Bandwidth Metric on the link during Flex-Algorithm SPF calculation.
When the computed link bandwidth is greater than or equal to When the computed link bandwidth is greater than or equal to
skipping to change at page 25, line 40 skipping to change at page 25, line 51
Juniper Networks Juniper Networks
salih@juniper.net salih@juniper.net
12. References 12. References
12.1. Normative References 12.1. Normative References
[I-D.ietf-lsr-flex-algo] [I-D.ietf-lsr-flex-algo]
Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and
A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex- A. Gulko, "IGP Flexible Algorithm", Work in Progress,
algo-15 (work in progress), April 2021. Internet-Draft, draft-ietf-lsr-flex-algo-18, 25 October
2021, <https://www.ietf.org/archive/id/draft-ietf-lsr-
flex-algo-18.txt>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
(TE) Extensions to OSPF Version 2", RFC 3630, (TE) Extensions to OSPF Version 2", RFC 3630,
DOI 10.17487/RFC3630, September 2003, DOI 10.17487/RFC3630, September 2003,
<https://www.rfc-editor.org/info/rfc3630>. <https://www.rfc-editor.org/info/rfc3630>.
skipping to change at page 26, line 19 skipping to change at page 26, line 32
[RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W.,
Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute
Advertisement", RFC 7684, DOI 10.17487/RFC7684, November Advertisement", RFC 7684, DOI 10.17487/RFC7684, November
2015, <https://www.rfc-editor.org/info/rfc7684>. 2015, <https://www.rfc-editor.org/info/rfc7684>.
12.2. Informative References 12.2. Informative References
[I-D.bashandy-rtgwg-segment-routing-uloop] [I-D.bashandy-rtgwg-segment-routing-uloop]
Bashandy, A., Filsfils, C., Litkowski, S., Decraene, B., Bashandy, A., Filsfils, C., Litkowski, S., Decraene, B.,
Francois, P., and P. Psenak, "Loop avoidance using Segment Francois, P., and P. Psenak, "Loop avoidance using Segment
Routing", draft-bashandy-rtgwg-segment-routing-uloop-10 Routing", Work in Progress, Internet-Draft, draft-
(work in progress), December 2020. bashandy-rtgwg-segment-routing-uloop-12, 22 December 2021,
<https://www.ietf.org/archive/id/draft-bashandy-rtgwg-
segment-routing-uloop-12.txt>.
[RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
Topology (MT) Routing in Intermediate System to Topology (MT) Routing in Intermediate System to
Intermediate Systems (IS-ISs)", RFC 5120, Intermediate Systems (IS-ISs)", RFC 5120,
DOI 10.17487/RFC5120, February 2008, DOI 10.17487/RFC5120, February 2008,
<https://www.rfc-editor.org/info/rfc5120>. <https://www.rfc-editor.org/info/rfc5120>.
[RFC5311] McPherson, D., Ed., Ginsberg, L., Previdi, S., and M. [RFC5311] McPherson, D., Ed., Ginsberg, L., Previdi, S., and M.
Shand, "Simplified Extension of Link State PDU (LSP) Space Shand, "Simplified Extension of Link State PDU (LSP) Space
for IS-IS", RFC 5311, DOI 10.17487/RFC5311, February 2009, for IS-IS", RFC 5311, DOI 10.17487/RFC5311, February 2009,
skipping to change at page 27, line 4 skipping to change at page 27, line 16
Previdi, "OSPF Traffic Engineering (TE) Metric Previdi, "OSPF Traffic Engineering (TE) Metric
Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015, Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015,
<https://www.rfc-editor.org/info/rfc7471>. <https://www.rfc-editor.org/info/rfc7471>.
[RFC8570] Ginsberg, L., Ed., Previdi, S., Ed., Giacalone, S., Ward, [RFC8570] Ginsberg, L., Ed., Previdi, S., Ed., Giacalone, S., Ward,
D., Drake, J., and Q. Wu, "IS-IS Traffic Engineering (TE) D., Drake, J., and Q. Wu, "IS-IS Traffic Engineering (TE)
Metric Extensions", RFC 8570, DOI 10.17487/RFC8570, March Metric Extensions", RFC 8570, DOI 10.17487/RFC8570, March
2019, <https://www.rfc-editor.org/info/rfc8570>. 2019, <https://www.rfc-editor.org/info/rfc8570>.
Authors' Addresses Authors' Addresses
Shraddha Hegde Shraddha Hegde
Juniper Networks Inc. Juniper Networks Inc.
Exora Business Park Exora Business Park
Bangalore, KA 560103 Bangalore 560103
KA
India India
Email: shraddha@juniper.net Email: shraddha@juniper.net
William Britto A J William Britto A J
Juniper Networks Inc. Juniper Networks Inc.
Email: bwilliam@juniper.net Email: bwilliam@juniper.net
Rajesh Shetty Rajesh Shetty
Juniper Networks Inc. Juniper Networks Inc.
Email: mrajesh@juniper.net Email: mrajesh@juniper.net
Bruno Decraene Bruno Decraene
Orange Orange
Email: bruno.decraene@orange.com Email: bruno.decraene@orange.com
Peter Psenak Peter Psenak
Cisco Systems Cisco Systems
Email: ppsenak@cisco.com Email: ppsenak@cisco.com
Tony Li Tony Li
Arista Networks Arista Networks
Email: tony.li@tony.li Email: tony.li@tony.li
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