--- 1/draft-ietf-mpls-rsvp-ingress-protection-01.txt 2014-10-26 17:15:21.177838850 -0700 +++ 2/draft-ietf-mpls-rsvp-ingress-protection-02.txt 2014-10-26 17:15:21.225840025 -0700 @@ -1,19 +1,19 @@ Internet Engineering Task Force H. Chen, Ed. Internet-Draft Huawei Technologies Intended status: Standards Track R. Torvi, Ed. -Expires: January 4, 2015 Juniper Networks - July 3, 2014 +Expires: April 29, 2015 Juniper Networks + October 26, 2014 Extensions to RSVP-TE for LSP Ingress Local Protection - draft-ietf-mpls-rsvp-ingress-protection-01.txt + draft-ietf-mpls-rsvp-ingress-protection-02.txt Abstract This document describes extensions to Resource Reservation Protocol - Traffic Engineering (RSVP-TE) for locally protecting the ingress node of a Traffic Engineered (TE) Label Switched Path (LSP) in a Multi- Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) network. Status of this Memo @@ -23,21 +23,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on January 4, 2015. + This Internet-Draft will expire on April 29, 2015. Copyright Notice Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -49,57 +49,56 @@ Table of Contents 1. Co-authors . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. An Example of Ingress Local Protection . . . . . . . . . . 3 2.2. Ingress Local Protection with FRR . . . . . . . . . . . . 4 3. Ingress Failure Detection . . . . . . . . . . . . . . . . . . 4 3.1. Source Detects Failure . . . . . . . . . . . . . . . . . . 4 3.2. Backup and Source Detect Failure . . . . . . . . . . . . . 5 - 3.3. Comparing Different Detection Modes . . . . . . . . . . . 5 4. Backup Forwarding State . . . . . . . . . . . . . . . . . . . 5 - 4.1. Forwarding State for Backup LSP . . . . . . . . . . . . . 6 + 4.1. Forwarding State for Backup LSP . . . . . . . . . . . . . 5 5. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . 6 5.1. INGRESS_PROTECTION Object . . . . . . . . . . . . . . . . 6 - 5.1.1. Subobject: Backup Ingress IPv4/IPv6 Address . . . . . 8 - 5.1.2. Subobject: Ingress IPv4/IPv6 Address . . . . . . . . . 9 - 5.1.3. Subobject: Traffic Descriptor . . . . . . . . . . . . 9 - 5.1.4. Subobject: Label-Routes . . . . . . . . . . . . . . . 10 - 6. Behavior of Ingress Protection . . . . . . . . . . . . . . . . 11 - 6.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 11 - 6.1.1. Relay-Message Method . . . . . . . . . . . . . . . . . 11 - 6.1.2. Proxy-Ingress Method . . . . . . . . . . . . . . . . . 11 - 6.1.3. Comparing Two Methods . . . . . . . . . . . . . . . . 12 - 6.2. Ingress Behavior . . . . . . . . . . . . . . . . . . . . . 13 - 6.2.1. Relay-Message Method . . . . . . . . . . . . . . . . . 13 - 6.2.2. Proxy-Ingress Method . . . . . . . . . . . . . . . . . 14 - 6.3. Backup Ingress Behavior . . . . . . . . . . . . . . . . . 15 - 6.3.1. Backup Ingress Behavior in Off-path Case . . . . . . . 15 - 6.3.2. Backup Ingress Behavior in On-path Case . . . . . . . 17 - 6.3.3. Failure Detection . . . . . . . . . . . . . . . . . . 18 - 6.4. Revertive Behavior . . . . . . . . . . . . . . . . . . . . 19 - 6.4.1. Revert to Primary Ingress . . . . . . . . . . . . . . 19 - 6.4.2. Global Repair by Backup Ingress . . . . . . . . . . . 19 - 7. Security Considerations . . . . . . . . . . . . . . . . . . . 20 - 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 - 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 20 - 10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 21 - 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 21 - 11.1. Normative References . . . . . . . . . . . . . . . . . . . 21 - 11.2. Informative References . . . . . . . . . . . . . . . . . . 22 - A. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 22 + 5.1.1. Subobject: Backup Ingress IPv4/IPv6 Address . . . . . 7 + 5.1.2. Subobject: Ingress IPv4/IPv6 Address . . . . . . . . . 8 + 5.1.3. Subobject: Traffic Descriptor . . . . . . . . . . . . 8 + 5.1.4. Subobject: Label-Routes . . . . . . . . . . . . . . . 9 + 6. Behavior of Ingress Protection . . . . . . . . . . . . . . . . 9 + 6.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 9 + 6.1.1. Relay-Message Method . . . . . . . . . . . . . . . . . 9 + 6.1.2. Proxy-Ingress Method . . . . . . . . . . . . . . . . . 10 + 6.1.3. Comparing Two Methods . . . . . . . . . . . . . . . . 11 + 6.2. Ingress Behavior . . . . . . . . . . . . . . . . . . . . . 11 + 6.2.1. Relay-Message Method . . . . . . . . . . . . . . . . . 12 + 6.2.2. Proxy-Ingress Method . . . . . . . . . . . . . . . . . 12 + 6.3. Backup Ingress Behavior . . . . . . . . . . . . . . . . . 13 + 6.3.1. Backup Ingress Behavior in Off-path Case . . . . . . . 14 + 6.3.2. Backup Ingress Behavior in On-path Case . . . . . . . 16 + 6.3.3. Failure Detection and Refresh PATH Messages . . . . . 17 + 6.4. Revertive Behavior . . . . . . . . . . . . . . . . . . . . 17 + 6.4.1. Revert to Primary Ingress . . . . . . . . . . . . . . 18 + 6.4.2. Global Repair by Backup Ingress . . . . . . . . . . . 18 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 18 + 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 + 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 19 + 10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 20 + 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 20 + 11.1. Normative References . . . . . . . . . . . . . . . . . . . 20 + 11.2. Informative References . . . . . . . . . . . . . . . . . . 21 + A. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 21 1. Co-authors - Ning So, Autumn Liu, Alia Atlas, Yimin Shen, Fengman Xu, Mehmet Toy, - Lei Liu + Ning So, Autumn Liu, Alia Atlas, Yimin Shen, Tarek Saad, Fengman Xu, + Mehmet Toy, Lei Liu 2. Introduction For MPLS LSPs it is important to have a fast-reroute method for protecting its ingress node as well as transit nodes. This is not covered either in the fast-reroute method defined in [RFC4090] or in the P2MP fast-reroute extensions to fast-reroute in [RFC4875]. An alternate approach to local protection (fast-reroute) is to use global protection and set up a second backup LSP (whether P2MP or @@ -125,55 +124,51 @@ : $ $ / / * $ : $ $ / / * [S] $ / / * $ $ / / * $ $/ / * [Ra]----[Rb] [L3] Figure 1: Backup P2MP LSP for Locally Protecting Ingress In normal operations, source S sends the traffic to primary ingress - R1. R1 imports the traffic into the primary LSP to egresses L1, L2 - and L3. + R1. R1 imports the traffic into the primary LSP. When source S detects the failure of R1, it switches the traffic to backup ingress Ra, which imports the traffic from S into the backup LSP to R1's next hops R2 and R4, where the traffic is merged into the primary LSP, and then sent to egresses L1, L2 and L3. Source S should be able to detect the failure of R1 and switch the - traffic within 10s of ms. The exact method by which S does so is out - of scope. + traffic within 10s of ms. Note that the backup ingress must be one logical hop away from the ingress. A logical hop is a direct link or a tunnel such as a GRE tunnel, over which RSVP-TE messages may be exchanged. 2.2. Ingress Local Protection with FRR Through using the ingress local protection and the FRR, we can - locally protect the ingress node, all the links and the intermediate - nodes of an LSP. The traffic switchover time is within tens of - milliseconds whenever the ingress, any of the links and the - intermediate nodes of the LSP fails. + locally protect the ingress, all the links and the transit nodes of + an LSP. The traffic switchover time is within 10s of ms whenever the + ingress, any of the links and the transit nodes of the LSP fails. The ingress node of the LSP can be locally protected through using - the ingress local protection. All the links and all the intermediate + the ingress local protection. All the links and all the transit nodes of the LSP can be locally protected through using the FRR. 3. Ingress Failure Detection - Exactly how the failure of the ingress (e.g. R1 in Figure 1) is - detected is out of scope for this document. However, it is necessary - to discuss different modes for detecting the failure because they - determine what must be signaled and what is the required behavior for - the traffic source and backup ingress. + Exactly how to detect the failure of the ingress is out of scope. + However, it is necessary to discuss different modes for detecting the + failure because they determine what is the required behavior for the + source and backup ingress. 3.1. Source Detects Failure Source Detects Failure or Source-Detect for short means that the source is responsible for fast detecting the failure of the primary ingress of an LSP. The backup ingress is ready to import the traffic from the source into the backup LSP after the backup LSP is up. In normal operations, the source sends the traffic to the primary ingress. When the source detects the failure of the primary ingress, @@ -189,58 +184,50 @@ through the backup LSP as needed. After the primary ingress fails, it will not be reachable after routing convergence. Thus checking whether the primary ingress (address) is reachable is a possible method. 3.2. Backup and Source Detect Failure Backup and Source Detect Failure or Backup-Source-Detect for short means that both the backup ingress and the source are concurrently - responsible for fast detecting the failures of the primary ingress. + responsible for fast detecting the failure of the primary ingress. In normal operations, the source sends the traffic to the primary ingress. It switches the traffic to the backup ingress when it detects the failure of the primary ingress. The backup ingress does not import any traffic from the source into the backup LSP in normal operations. When it detects the failure of the primary ingress, it imports the traffic from the source into the backup LSP to the next hops of the primary ingress, where the traffic is merged into the primary LSP. - Note that the source may locally distinguish between the failure of - the primary ingress and that of the link between the source and the - primary ingress. When the source detects the failure of the link, it - may continue to send the traffic to the primary ingress via another - link between the source and the primary ingress if there is one. - -3.3. Comparing Different Detection Modes - The source-detect is preferred. It is simpler than the backup- source-detect, which needs both the source and the backup ingress - detect the ingress failaure quickly. + detect the ingress failure quickly. 4. Backup Forwarding State Before the primary ingress fails, the backup ingress is responsible for creating the necessary backup LSPs. These LSPs might be multiple bypass P2P LSPs that avoid the ingress. Alternately, the backup ingress could choose to use a single backup P2MP LSP as a bypass or detour to protect the primary ingress of a primary P2MP LSP. - The backup ingress may be off-path or on-path of an LSP. When a - backup ingress is not any node of the LSP, we call the backup ingress - is off-path. When a backup ingress is a next-hop of the primary - ingress of the LSP, we call it is on-path. If the backup ingress is - on-path, the primary forwarding state associated with the primary LSP - SHOULD be clearly separated from the backup LSP(s) state. + The backup ingress may be off-path or on-path of an LSP. If a backup + ingress is not any node of the LSP, we call it is off-path. If a + backup ingress is a next-hop of the primary ingress of the LSP, we + call it is on-path. If it is on-path, the primary forwarding state + associated with the primary LSP SHOULD be clearly separated from the + backup LSP(s) state. 4.1. Forwarding State for Backup LSP A forwarding entry for a backup LSP is created on the backup ingress after the LSP is set up. Depending on the failure-detection mode (e.g., source-detect), it may be used to forward received traffic or simply be inactive (e.g., backup-source-detect) until required. In either case, when the primary ingress fails, this entry is used to import the traffic into the backup LSP to the next hops of the primary ingress, where the traffic is merged into the primary LSP. @@ -267,33 +254,33 @@ Class-Num = TBD C-Type = TBD 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length (bytes) | Class-Num | C-Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Secondary LSP ID | Flags | Options | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ (Subobjects) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + Flags 0x01 Ingress local protection available 0x02 Ingress local protection in use 0x04 Bandwidth protection Options 0x01 Revert to Ingress - 0x02 Ingress-Proxy/Relay-Message - 0x04 P2MP Backup + 0x02 P2MP Backup The Secondary LSP ID in the object is an LSP ID that the primary ingress has allocated for a protected LSP tunnel. The backup ingress - will use this LSP ID to set up a new LSP from the backup ingress to + may use this LSP ID to set up a new LSP from the backup ingress to the destinations of the protected LSP tunnel. This allows the new LSP to share resources with the old one. The flags are used to communicate status information from the backup ingress to the primary ingress. o Ingress local protection available: The backup ingress sets this flag after backup LSPs are up and ready for locally protecting the primary ingress. The backup ingress sends this to the primary ingress to indicate that the primary ingress is locally protected. @@ -301,201 +288,142 @@ o Ingress local protection in use: The backup ingress sets this flag when it detects a failure in the primary ingress. The backup ingress keeps it and does not send it to the primary ingress since the primary ingress is down. o Bandwidth protection: The backup ingress sets this flag if the backup LSPs guarantee to provide desired bandwidth for the protected LSP against the primary ingress failure. The options are used by the primary ingress to specify the desired - behavior to the backup ingress and next-hops. + behavior to the backup ingress. o Revert to Ingress: The primary ingress sets this option indicating that the traffic for the primary LSP successfully re-signaled will be switched back to the primary ingress from the backup ingress when the primary ingress is restored. - o Ingress-Proxy/Relay-Message: This option is set to one indicating - that Ingress-Proxy method is used. It is set to zero indicating - that Relay-Message method is used. - o P2MP Backup: This option is set to ask for the backup ingress to use P2MP backup LSP to protect the primary ingress. Note that one spare bit of the flags in the FAST-REROUTE object can be used to indicate whether P2MP or P2P backup LSP is desired for protecting - an ingress and intermediate node. + an ingress and transit node. - The INGRESS_PROTECTION object may contain some of the sub objects - described below. + The INGRESS_PROTECTION object may contain some sub objects below. 5.1.1. Subobject: Backup Ingress IPv4/IPv6 Address When the primary ingress of a protected LSP sends a PATH message with an INGRESS_PROTECTION object to the backup ingress, the object may have a Backup Ingress IPv4/IPv6 Address sub object containing an - IPv4/IPv6 address belonging to the backup ingress. The formats of - the sub object for Backup Ingress IPv4/IPv6 Address is given below: - - 0 1 2 3 - 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Type | Length | Reserved (zeros) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | IPv4 address | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - - Type: TBD-1 Backup Ingress IPv4 Address - Length: Total length of the subobject in bytes, including - the Type and Length fields. The Length is always 8. - Reserved: Reserved two bytes are set to zeros. - IPv4 address: A 32-bit unicast, host address. + IPv4/IPv6 address belonging to the backup ingress. The Type of the + sub object is TBD-1/TBD-2 for Backup Ingress IPv4/IPv6 Address. The + body of the sub object is given below: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Type | Length | Reserved (zeros) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | | - ~ IPv6 address (16 bytes) ~ + | IPv4/IPv6 address (4/16 bytres) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Type: TBD-2 Backup Ingress IPv6 Address - Length: Total length of the subobject in bytes, including - the Type and Length fields. The Length is always 20. - Reserved: Reserved two bytes are set to zeros. - IPv6 address: A 128-bit unicast, host address. + IPv4/IPv6 address: A 32/128-bit unicast, host address. 5.1.2. Subobject: Ingress IPv4/IPv6 Address The INGRESS_PROTECTION object may have an Ingress IPv4/IPv6 Address sub object containing an IPv4/IPv6 address belonging to the primary - ingress. The sub object has the following format: - - 0 1 2 3 - 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Type | Length | Reserved (zeros) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | IPv4 address | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - - Type: TBD-3 Ingress IPv4 Address - Length: Total length of the subobject in bytes, including - the Type and Length fields. The Length is always 8. - Reserved: Reserved two bytes are set to zeros. - IPv4 address: A 32-bit unicast, host address. + ingress. The Type of the sub object is TBD-3/TBD-4 for Ingress IPv4/ + IPv6 Address. The sub object has the following body: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Type | Length | Reserved (zeros) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | | - ~ IPv6 address (16 bytes) ~ + | IPv4/IPv6 address (4/16 bytres) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Type: TBD-4 Backup Ingress IPv6 Address - Length: Total length of the subobject in bytes, including - the Type and Length fields. The Length is always 20. - Reserved: Reserved two bytes are set to zeros. - IPv6 address: A 128-bit unicast, host address. + IPv4/IPv6 address: A 32/128-bit unicast, host address. 5.1.3. Subobject: Traffic Descriptor The INGRESS_PROTECTION object may have a Traffic Descriptor sub object describing the traffic to be mapped to the backup LSP on the - backup ingress for locally protecting the primary ingress. The sub - object has the following format: + backup ingress for locally protecting the primary ingress. The Type + of the sub object is TBD-5/TBD-6/TBD-7 for Interface/IPv4/6 Prefix + respectively. The sub object has the following body: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Type | Length | Reserved (zeros) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Traffic Element 1 | ~ ~ | Traffic Element n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Type: TBD-5/TBD-6/TBD-7 Interface/IPv4/6 Prefix - Length: Total length of the subobject in bytes, including - the Type and Length fields. - Reserved: Reserved two bytes are set to zeros. - The Traffic Descriptor sub object may contain multiple Traffic - Elements of same type as follows. + Elements of same type as follows: o Interface Traffic (Type TBD-5): Each of the Traffic Elements is a 32 bit index of an interface, from which the traffic is imported into the backup LSP. o IPv4/6 Prefix Traffic (Type TBD-6/TBD-7): Each of the Traffic Elements is an IPv4/6 prefix, containing an 8-bit prefix length followed by an IPv4/6 address prefix, whose length, in bits, was specified by the prefix length, padded to a byte boundary. 5.1.4. Subobject: Label-Routes The INGRESS_PROTECTION object in a PATH message from the primary ingress to the backup ingress will have a Label-Routes sub object containing the labels and routes that the next hops of the ingress - use. The sub object has the following format: + use. The Type of the sub object is TBD-8. The sub object has the + following body: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Type | Length | Reserved (zeros) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - ~ (Subobjects) ~ + ~ Subobjects ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Type: TBD-8 Label-Routes - Length: Total length of the subobject in bytes, including - the Type and Length fields. - Reserved: Reserved two bytes are set to zeros. - - The Subobjects in the Label-Routes are copied from the Subobjects in - the RECORD_ROUTE objects contained in the RESV messages that the - primary ingress receives from its next hops for the protected LSP. - They MUST contain the first hops of the LSP, each of which is paired - with its label. + The Subobjects in the Label-Routes are copied from those in the + RECORD_ROUTE objects in the RESV messages that the primary ingress + receives from its next hops for the primary LSP. They MUST contain + the first hops of the LSP, each of which is paired with its label. 6. Behavior of Ingress Protection 6.1. Overview There are four parts of ingress protection: 1) setting up the necessary backup LSP forwarding state; 2) identifying the failure and - providing the fast repair (as discussed in Sections 2 and 3); 3) + providing the fast repair (as discussed in Sections 3 and 4); 3) maintaining the RSVP-TE control plane state until a global repair can - be done; and 4) performing the global repair(see Section 5.5). + be done; and 4) performing the global repair(see Section 6.4). There are two different proposed signaling approaches to obtain - ingress protection. They both use the same new INGRESS-PROTECTION + ingress protection. They both use the same new INGRESS_PROTECTION object. The object is sent in both PATH and RESV messages. 6.1.1. Relay-Message Method The primary ingress relays the information for ingress protection of an LSP to the backup ingress via PATH messages. Once the LSP is created, the ingress of the LSP sends the backup ingress a PATH - message with an INGRESS-PROTECTION object with Label-Routes + message with an INGRESS_PROTECTION object with Label-Routes subobject, which is populated with the next-hops and labels. This provides sufficient information for the backup ingress to create the appropriate forwarding state and backup LSP(s). The ingress also sends the backup ingress all the other PATH messages - for the LSP with an empty INGRESS-PROTECTION object. Thus, the + for the LSP with an empty INGRESS_PROTECTION object. Thus, the backup ingress has access to all the PATH messages needed for - modification to be sent to refresh control-plane state after a - failure. + modification to refresh control-plane state after a failure. The advantages of this method include: 1) the primary LSP is independent of the backup ingress; 2) simple; 3) less configuration; and 4) less control traffic. 6.1.2. Proxy-Ingress Method Conceptually, a proxy ingress is created that starts the RSVP signaling. The explicit path of the LSP goes from the proxy ingress to the backup ingress and then to the real ingress. The behavior and @@ -510,21 +438,21 @@ [ & ingress ] | * | *****[ MP ]----| Figure 2: Example Protected LSP with Proxy Ingress Node The backup ingress must know the merge points or next-hops and their associated labels. This is accomplished by having the RSVP PATH and RESV messages go through the backup ingress, although the forwarding path need not go through the backup ingress. If the backup ingress - fails, the ingress simply removes the INGRESS-PROTECTION object and + fails, the ingress simply removes the INGRESS_PROTECTION object and forwards the PATH messages to the LSP's next-hop(s). If the ingress has its LSP configured for ingress protection, then the ingress can add the backup ingress and itself to the ERO and start forwarding the PATH messages to the backup ingress. Slightly different behavior can apply for the on-path and off-path cases. In the on-path case, the backup ingress is a next hop node after the ingress for the LSP. In the off-path, the backup ingress is not any next-hop node after the ingress for all associated sub- LSPs. @@ -549,21 +477,21 @@ |Proxy- | Yes |Yes- | Yes | Yes | Yes | |Ingress| | | | | | +-------+-----------+------+--------+-----------------+---------+ 6.2. Ingress Behavior The primary ingress must be configured with two or three pieces of information for ingress protection. o Backup Ingress Address: The primary ingress must know an IP - address for it to be included in the INGRESS-PROTECTION object. + address for it to be included in the INGRESS_PROTECTION object. o Proxy-Ingress-Id (only needed for Proxy-Ingress Method): The Proxy-Ingress-Id is only used in the Record Route Object for recording the proxy-ingress. If no proxy-ingress-id is specified, then a local interface address that will not otherwise be included in the Record Route Object can be used. A similar technique is used in [RFC4090 Sec 6.1.1]. o Application Traffic Identifier: The primary ingress and backup ingress must both know what application traffic should be directed @@ -579,137 +507,135 @@ With this additional information, the primary ingress can create and signal the necessary RSVP extensions to support ingress protection. 6.2.1. Relay-Message Method To protect the ingress of an LSP, the ingress does the following after the LSP is up. 1. Select a PATH message. - 2. If the backup ingress is off-path, then send the backup ingress a - PATH message with the content from the selected PATH message and - an INGRESS-PROTECTION object; else (the backup ingress is a next - hop, i.e., on-path case) add an INGRESS-PROTECTION object into + 2. If the backup ingress is off-path, then send it a PATH message + with the content from the selected PATH message and an + INGRESS_PROTECTION object; else (the backup ingress is a next + hop, i.e., on-path case) add an INGRESS_PROTECTION object into the existing PATH message to the backup ingress (i.e., the next - hop). The INGRESS-PROTECTION object contains the Traffic- - Descriptor sub-object, the Backup Ingress Address sub-object and - the Label-Routes sub-object. The flags is set to indicate - whether a Backup P2MP LSP is desired. If not yet allocated, - allocate a second LSP-ID to be used in the INGRESS-PROTECTION - object. The Label-Routes sub-object contains the next-hops of - the ingress and their labels. + hop). The object contains the Traffic-Descriptor sub-object, the + Backup Ingress Address sub-object and the Label-Routes sub- + object. The flags is set to indicate whether a Backup P2MP LSP + is desired. A second LSP-ID is allocated (if it is not allocated + yet) and used in the object. The Label-Routes sub-object + contains the next-hops of the ingress and their labels. - 3. For each of the other PATH messages, if the node to which the - message is sent is not the backup ingress, then send the backup - ingress a PATH message with the content copied from the message - to the node and an empty INGRESS-PROTECTION object; else send the - node the message with an empty INGRESS-PROTECTION object. + 3. For each of the other PATH messages, send the backup ingress a + PATH message with the content copied from the message and an + empty INGRESS_PROTECTION object, which is an object without any + Traffic-Descriptor sub-object. 6.2.2. Proxy-Ingress Method The primary ingress is responsible for starting the RSVP signaling for the proxy-ingress node. To do this, the following is done for the RSVP PATH message. 1. Compute the EROs for the LSP as normal for the ingress. 2. If the selected backup ingress node is not the first node on the path (for all sub-LSPs), then insert at the beginning of the ERO first the backup ingress node and then the ingress node. 3. In the PATH RRO, instead of recording the ingress node's address, replace it with the Proxy-Ingress-Id. 4. Leave the HOP object populated as usual with information for the ingress-node. - 5. Add the INGRESS-PROTECTION object to the PATH message. Allocate + 5. Add the INGRESS_PROTECTION object to the PATH message. Allocate a second LSP-ID to be used in the INGRESS-PROTECTION object. Include the Backup Ingress Address (IPv4 or IPv6) sub-object and the Traffic-Descriptor sub-object. Set or clear the flag indicating that a Backup P2MP LSP is desired. 6. Optionally, add the FAST-REROUTE object [RFC4090] to the Path message. Indicate whether one-to-one backup is desired. Indicate whether facility backup is desired. 7. The RSVP PATH message is sent to the backup node as normal. If the ingress detects that it can't communicate with the backup ingress, then the ingress should instead send the PATH message to the next-hop indicated in the ERO computed in step 1. Once the ingress detects that it can communicate with the backup ingress, the ingress SHOULD follow the steps 1-7 to obtain ingress failure protection. When the ingress node receives an RSVP PATH message with an INGRESS- PROTECTION object and the object specifies that node as the ingress node and the PHOP as the backup ingress node, the ingress node SHOULD - remove the INGRESS-PROTECTION object from the PATH message before + remove the INGRESS_PROTECTION object from the PATH message before sending it out. Additionally, the ingress node must store that it will install ingress forwarding state for the LSP rather than midpoint forwarding. When an RSVP RESV message is received by the ingress, it uses the NHOP to determine whether the message is received from the backup ingress or from a different node. The stored associated PATH message - contains an INGRESS-PROTECTION object that identifies the backup + contains an INGRESS_PROTECTION object that identifies the backup ingress node. If the RESV message is not from the backup node, then - ingress forwarding state should be set up, and the INGRESS-PROTECTION + ingress forwarding state should be set up, and the INGRESS_PROTECTION object MUST be added to the RESV before it is sent to the NHOP, which should be the backup node. If the RESV message is from the backup node, then the LSP should be considered available for use. If the backup ingress node is on the forwarding path, then a RESV is - received with an INGRESS-PROTECTION object and an NHOP that matches + received with an INGRESS_PROTECTION object and an NHOP that matches the backup ingress. In this case, the ingress node's address will not appear after the backup ingress in the RRO. The ingress node should set up ingress forwarding state, just as is done if the LSP weren't ingress-node protected. 6.3. Backup Ingress Behavior An LER determines that the ingress local protection is requested for an LSP if the INGRESS_PROTECTION object is included in the PATH message it receives for the LSP. The LER can further determine that it is the backup ingress if one of its addresses is in the Backup - Ingress Address sub-object of the INGRESS-PROTECTION object. The LER + Ingress Address sub-object of the INGRESS_PROTECTION object. The LER as the backup ingress will assume full responsibility of the ingress after the primary ingress fails. In addition, the LER determines that it is off-path if it is not a next hop of the primary ingress. 6.3.1. Backup Ingress Behavior in Off-path Case The backup ingress considers itself as a PLR and the primary ingress as its next hop and provides a local protection for the primary ingress. It behaves very similarly to a PLR providing fast-reroute where the primary ingress is considered as the failure-point to protect. Where not otherwise specified, the behavior given in [RFC4090] for a PLR should apply. The backup ingress SHOULD follow the control-options specified in the - INGRESS-PROTECTION object and the flags and specifications in the + INGRESS_PROTECTION object and the flags and specifications in the FAST-REROUTE object. This applies to providing a P2MP backup if the "P2MP backup" is set, a one-to-one backup if "one-to-one desired" is set, facility backup if the "facility backup desired" is set, and backup paths that support the desired bandwidth, and administrative- colors that are requested. - If multiple INGRESS-PROTECTION objects have been received via - multiple PATH messages for the same LSP, then the most recent one - that specified a Traffic-Descriptor sub-object MUST be the one used. + If multiple non empty INGRESS_PROTECTION objects have been received + via multiple PATH messages for the same LSP, then the most recent one + MUST be the one used. The backup ingress creates the appropriate forwarding state for the backup LSP tunnel(s) to the merge point(s). When the backup ingress sends a RESV message to the primary ingress, - it should add an INGRESS-PROTECTION object into the message. It + it should add an INGRESS_PROTECTION object into the message. It SHOULD set or clear the flags in the object to report "Ingress local protection available", "Ingress local protection in use", and "bandwidth protection". If the backup ingress doesn't have a backup LSP tunnel to all the merge points, it SHOULD clear "Ingress local protection available". [Editor Note: It is possible to indicate the number or which are unprotected via a sub-object if desired.] When the primary ingress fails, the backup ingress redirects the @@ -734,74 +660,73 @@ occur, then the standard RSVP soft-state removal SHOULD occur. The backup ingress SHALL remove the state for the PATH message from the primary ingress, and tear down the one-to-one backup LSPs for protecting the primary ingress if one-to-one backup is used or unbind the facility backup LSPs if facility backup is used. When the backup ingress receives a PATH message from the primary ingress for locally protecting the primary ingress of a protected LSP, it checks to see if any critical information has been changed. If the next hops of the primary ingress are changed, the backup - ingress SHALL update its backup LSP(s). + ingress SHALL update its backup LSP(s) accordingly. 6.3.1.1. Relay-Message Method - When the backup ingress receives a PATH message with the INGRESS- - PROTECTION object, it examines the object to learn what traffic - associated with the LSP. It determines the next-hops to be merged to - by examining the Label-Routes sub-object in the object. If the - Traffic-Descriptor sub-object isn't included, this object is - considered "empty". + When the backup ingress receives a PATH message with an non empty + INGRESS_PROTECTION object, it examines the object to learn what + traffic associated with the LSP. It determines the next-hops to be + merged to by examining the Label-Routes sub-object in the object. The backup ingress stores the PATH message received from the primary ingress, but does NOT forward it. The backup ingress MUST respond with a RESV to the PATH message - received from the primary ingress. If the INGRESS-PROTECTION object + received from the primary ingress. If the INGRESS_PROTECTION object is not "empty", the backup ingress SHALL send the RESV message with the state indicating protection is available after the backup LSP(s) are successfully established. 6.3.1.2. Proxy-Ingress Method The backup ingress determines the next-hops to be merged to by collecting the set of the pair of (IPv4/IPv6 sub-object, Label sub- object) from the Record Route Object of each RESV that are closest to the top and not the Ingress router; this should be the second to the - top pair. If a Label-Routes sub-object is included in the INGRESS- - PROTECTION object, the included IPv4/IPv6 sub-objects are used to - filter the set down to the specific next-hops where protection is - desired. A RESV message must have been received before the Backup - Ingress can create or select the appropriate backup LSP. + top pair. If a Label-Routes sub-object is included in the + INGRESS_PROTECTION object, the included IPv4/IPv6 sub-objects are + used to filter the set down to the specific next-hops where + protection is desired. A RESV message must have been received before + the Backup Ingress can create or select the appropriate backup LSP. - When the backup ingress receives a PATH message with the INGRESS- - PROTECTION object, the backup ingress examines the object to learn - what traffic associated with the LSP. The backup ingress forwards - the PATH message to the ingress node with the normal RSVP changes. + When the backup ingress receives a PATH message with the + INGRESS_PROTECTION object, the backup ingress examines the object to + learn what traffic associated with the LSP. The backup ingress + forwards the PATH message to the ingress node with the normal RSVP + changes. - When the backup ingress receives a RESV message with the INGRESS- - PROTECTION object, the backup ingress records an IMPLICIT-NULL label - in the RRO. Then the backup ingress forwards the RESV message to the - ingress node, which is acting for the proxy ingress. + When the backup ingress receives a RESV message with the + INGRESS_PROTECTION object, the backup ingress records an IMPLICIT- + NULL label in the RRO. Then the backup ingress forwards the RESV + message to the ingress node, which is acting for the proxy ingress. 6.3.2. Backup Ingress Behavior in On-path Case An LER as the backup ingress determines that it is on-path if one of - its addresses is a next hop of the primary ingress and the primary + its addresses is a next hop of the primary ingress (and the primary ingress is not its next hop via checking the PATH message with the - INGRESS_PROTECTION object received from the primary ingress. The LER - on-path sends the corresponding PATH messages without any - INGRESS_PROTECTION object to its next hops. It creates a number of - backup P2P LSPs or a backup P2MP LSP from itself to the other next - hops (i.e., the next hops other than the backup ingress) of the - primary ingress. The other next hops are from the Label-Routes sub - object. + INGRESS_PROTECTION object received from the primary ingress for + Proxy-Ingress Method). The LER on-path sends the corresponding PATH + messages without any INGRESS_PROTECTION object to its next hops. It + creates a number of backup P2P LSPs or a backup P2MP LSP from itself + to the other next hops (i.e., the next hops other than the backup + ingress) of the primary ingress. The other next hops are from the + Label-Routes sub object. It also creates a forwarding entry, which sends/multicasts the traffic from the source to the next hops of the backup ingress along the protected LSP when the primary ingress fails. The traffic is described by the Traffic-Descriptor. After the forwarding entry is created, all the backup P2P LSPs or the backup P2MP LSP is up and associated with the protected LSP, the backup ingress sends the primary ingress the RESV message with the INGRESS_PROTECTION object containing the state of the local @@ -814,37 +739,41 @@ backup P2MP LSP transmitting the traffic to the other next hops of the primary ingress, where the traffic is merged into protected LSP. During the local repair, the backup ingress continues to send the PATH messages to its next hops as before, keeps the PATH message with the INGRESS_PROTECTION object received from the primary ingress and the RESV message with the INGRESS_PROTECTION object to be sent to the primary ingress. It sets the "local protection in use" flag in the RESV message. -6.3.3. Failure Detection +6.3.3. Failure Detection and Refresh PATH Messages As described in [RFC4090], it is necessary to refresh the PATH messages via the backup LSP(s). The Backup Ingress MUST wait to - refresh the backup PATH messages until it can accurately detect that - the ingress node has failed. An example of such an accurate - detection would be that the IGP has no bi-directional links to the - ingress node and the last change was long enough in the past that - changes should have been received (i.e., an IGP network convergence - time or approximately 2-3 seconds) or a BFD session to the primary - ingress' loopback address has failed and stayed failed after the - network has reconverged. + refresh the PATH messages until it can accurately detect that the + ingress node has failed. An example of such an accurate detection + would be that the IGP has no bi-directional links to the ingress node + and the last change was long enough in the past that changes should + have been received (i.e., an IGP network convergence time or + approximately 2-3 seconds) or a BFD session to the primary ingress' + loopback address has failed and stayed failed after the network has + reconverged. As described in [RFC4090 Section 6.4.3], the backup ingress, acting - as PLR, SHOULD modify - including removing any INGRESS-PROTECTION and - FAST-REROUTE objects - and send any saved PATH messages associated - with the primary LSP. + as PLR, SHOULD modify and send any saved PATH messages associated + with the primary LSP to the corresponding next hops through backup + LSP(s). Any PATH message sent will not contain any + INGRESS_PROTECTION object. The RSVP_HOP object in the message + contains an IP source address belonging to the backup ingress. The + sender template object has the backup ingress address as its tunnel + sender address. 6.4. Revertive Behavior Upon a failure event in the (primary) ingress of a protected LSP, the protected LSP is locally repaired by the backup ingress. There are a couple of basic strategies for restoring the LSP to a full working path. - Revert to Primary Ingress: When the primary ingress is restored, it re-signals each of the LSPs that start from the primary @@ -860,50 +789,49 @@ If "Revert to Primary Ingress" is desired for a protected LSP, the (primary) ingress of the LSP re-signals the LSP that starts from the primary ingress after the primary ingress restores. When the LSP is re-signaled successfully, the traffic is switched back to the primary ingress from the backup ingress and redirected into the LSP starting from the primary ingress. If the ingress can resignal the PATH messages for the LSP, then the ingress can specify the "Revert to Ingress" control-option in the - INGRESS-PROTECTION object. Doing so may cause a duplication of + INGRESS_PROTECTION object. Doing so may cause a duplication of traffic while the Ingress starts sending traffic again before the Backup Ingress stops; the alternative is to drop traffic for a short period of time. Additionally, the Backup Ingress can set the "Revert To Ingress" control-option as a request for the Ingress to take over. 6.4.2. Global Repair by Backup Ingress When the backup ingress has determined that the primary ingress of the protected LSP has failed (e.g., via the IGP), it can compute a new path and signal a new LSP along the new path so that it no longer relies upon local repair. To do this, the backup ingress uses the same tunnel sender address in the Sender Template Object and uses the - previously allocated second LSP-ID in the INGRESS-PROTECTION object + previously allocated second LSP-ID in the INGRESS_PROTECTION object of the PATH message as the LSP-ID of the new LSP. This allows the new LSP to share resources with the old LSP. In addition, if the Ingress recovers, the Backup Ingress SHOULD send it RESVs with the - INGRESS-PROTECTION object where either the "Force to Backup" or - "Revert to Ingress" is specified. The Secondary LSP ID should be the - unused LSP ID - while the LSP ID signaled in the RESV will be that - currently active. The Ingress can learn from the RESVs what to - signal. Even if the Ingress does not take over, the RESVs notify it - that the particular LSP IDs are in use. The Backup Ingress can - reoptimize the new LSP as necessary until the Ingress recovers. - Alternately, the Backup Ingress can create a new LSP with no - bandwidth reservation that duplicates the path(s) of the protected - LSP, move traffic to the new LSP, delete the protected LSP, and then - resignal the new LSP with bandwidth. + INGRESS_PROTECTION object where the "Revert to Ingress" is specified. + The Secondary LSP ID should be the unused LSP ID - while the LSP ID + signaled in the RESV will be that currently active. The Ingress can + learn from the RESVs what to signal. Even if the Ingress does not + take over, the RESVs notify it that the particular LSP IDs are in + use. The Backup Ingress can reoptimize the new LSP as necessary + until the Ingress recovers. Alternately, the Backup Ingress can + create a new LSP with no bandwidth reservation that duplicates the + path(s) of the protected LSP, move traffic to the new LSP, delete the + protected LSP, and then resignal the new LSP with bandwidth. 7. Security Considerations In principle this document does not introduce new security issues. The security considerations pertaining to RFC 4090, RFC 4875 and other RSVP protocols remain relevant. 8. IANA Considerations TBD @@ -939,23 +868,24 @@ Markus Jork Juniper Networks 10 Technology Park Drive Westford, MA 01886 USA Email: mjork@juniper.net 10. Acknowledgement The authors would like to thank Nobo Akiya, Rahul Aggarwal, Eric - Osborne, Ross Callon, Loa Andersson, Michael Yue, Olufemi Komolafe, - Rob Rennison, Neil Harrison, Kannan Sampath, and Ronhazli Adam for - their valuable comments and suggestions on this draft. + Osborne, Ross Callon, Loa Andersson, Daniel King, Michael Yue, + Olufemi Komolafe, Rob Rennison, Neil Harrison, Kannan Sampath, and + Ronhazli Adam for their valuable comments and suggestions on this + draft. 11. References 11.1. Normative References [RFC1700] Reynolds, J. and J. Postel, "Assigned Numbers", RFC 1700, October 1994. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. @@ -1000,60 +930,65 @@ [RFC2702] Awduche, D., Malcolm, J., Agogbua, J., O'Dell, M., and J. McManus, "Requirements for Traffic Engineering Over MPLS", RFC 2702, September 1999. [RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y., Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack Encoding", RFC 3032, January 2001. Appendix A. Authors' Addresses + Huaimo Chen Huawei Technologies Boston, MA USA Email: huaimo.chen@huawei.com + Raveendra Torvi + Juniper Networks + 10 Technology Park Drive + Westford, MA 01886 + USA + Email: rtorvi@juniper.net + Ning So Tata Communications 2613 Fairbourne Cir. Plano, TX 75082 USA Email: ningso01@gmail.com - Autumn Liu Ericsson 300 Holger Way San Jose, CA 95134 USA Email: autumn.liu@ericsson.com - Raveendra Torvi - Juniper Networks - 10 Technology Park Drive - Westford, MA 01886 - USA - Email: rtorvi@juniper.net - Alia Atlas Juniper Networks 10 Technology Park Drive Westford, MA 01886 USA Email: akatlas@juniper.net + Yimin Shen Juniper Networks 10 Technology Park Drive Westford, MA 01886 USA Email: yshen@juniper.net + Tarek Saad + Cisco Systems + Email: tsaad@cisco.com + Fengman Xu Verizon 2400 N. Glenville Dr Richardson, TX 75082 USA Email: fengman.xu@verizon.com Mehmet Toy Comcast 1800 Bishops Gate Blvd.