CCAMP Working Group D. Caviglia Internet-Draft D. Ceccarelli Intended status: Standards Track D. Bramanti Expires: January 28, 2010 Ericsson D. Li Huawei Technologies S. Bardalai Fujitsu Network July 27, 2009 RSVP-TE Signaling Extension For Management Plane To Control Plane LSP Handover In A GMPLS Enabled Transport Network. draft-ietf-ccamp-pc-spc-rsvpte-ext-03 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on January 28, 2010. Copyright Notice Copyright (c) 2009 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 in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Caviglia, et al. Expires January 28, 2010 [Page 1] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 Abstract We would like to dedicate this work to our friend and colleague Dino Bramanti, who passed away at the early age of 38. Dino has been involved in this work since its beginning. In a transport network scenario, where Data Plane connections controlled either by GMPLS Control Plane (Soft Permanent Connections - SPC) or by Management System (Permanent Connections - PC) may independently coexist, the ability of transforming an existing PC into a SPC and vice versa - without actually affecting Data Plane traffic being carried over it - is a requirement [RFC5493]. This memo provides a minor extension to RSVP-TE [RFC2205], [RFC3471], [RFC3473], [RFC4872] signaling protocol, within GMPLS architecture, to enable such connection ownership transfer and describes the defined procedures. Failure conditions and subsequent roll back are also defined taking into account that an handover failure MUST NOT impact the already established data plane connections. Caviglia, et al. Expires January 28, 2010 [Page 2] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. MP to CP handover: LSP Ownership Transfer From Management Plane To Control Plane . . . . . . . . . . . . 5 4.2. MP to CP Handover Procedure Failure Handling . . . . . . . 6 4.2.1. MP to CP Handover Failure - Path Failure . . . . . . . 6 4.2.1.1. MP to CP Handover Failure - Path message and Data Plane Failure . . . . . . . . . . . . . . . . 6 4.2.1.2. MP to CP Handover Failure - Path message and Communication failure . . . . . . . . . . . . . . 7 4.2.2. MP to CP Handover Failure - Resv Error . . . . . . . . 8 4.2.2.1. MP to CP Handover Failure - Resv Error and Data Plane failure . . . . . . . . . . . . . . . . 8 4.2.2.2. MP to CP Handover Failure - Resv Error and Communication failure . . . . . . . . . . . . . . 9 4.2.2.3. MP to CP Handover Failure - Node Graceful Restart . . . . . . . . . . . . . . . . . . . . . 10 4.3. CP to MP handover : LSP Ownership Transfer From Control Plane To Management Plane . . . . . . . . . . . . 13 4.4. CP to MP Handover Procedure Failure . . . . . . . . . . . 13 5. Alternative Way Of Retrieving Information Needed For MP To CP Handover . . . . . . . . . . . . . . . . . . . . . . . . . 14 6. RSVP Message Formats . . . . . . . . . . . . . . . . . . . . . 15 7. Objects Modification . . . . . . . . . . . . . . . . . . . . . 15 7.1. Administrative Status Object . . . . . . . . . . . . . . . 15 7.2. Error Spec Object . . . . . . . . . . . . . . . . . . . . 16 8. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 16 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 17 11. Security Considerations . . . . . . . . . . . . . . . . . . . 17 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18 13.1. Normative References . . . . . . . . . . . . . . . . . . . 18 13.2. Informational References . . . . . . . . . . . . . . . . . 18 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19 Caviglia, et al. Expires January 28, 2010 [Page 3] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 1. Introduction In a typical traditional transport network scenario, Data Plane (DP) connections between two endpoints are controlled by means of a Network Management System (NMS) operating within Management Plane (MP). NMS/MP is the owner of such transport connections, being responsible of their set up, tear down and maintenance. The adoption of a GMPLS Control Plane (CP) over networks that are already in service - controlled by NMS at MP level - introduces the need for a procedure able to coordinate a control handover of a generic data plane connection from MP to CP. In addition, the control handover in the opposite direction, from CP to MP SHOULD be possible as well. The procedures described in this memo can be applied to any kind of LSP and network architecture. 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 3. Motivation The main motivation behind this work is the definition of a simple and very low impacting procedure that satisfies the requirements defined in [RFC5493]. Such procedure is aimed at giving the transport network operators the chance to handover the ownership of existing LSPs provisioned by NMS from the MP to the CP without disrupting user traffic flowing on them. Handover from MP to CP (i.e. when existing DP connection ownership and control is passed from MP to CP) has been defined as mandatory requirement, while the opposite operation, CP to MP handover, has been considered as a nice- to-have feature that can be seen as an emergency procedure to disable the CP and take the manual control of the LSP. For more details on requirements and motivations please refer to [RFC5493]. 4. Procedures The modification defined in this document refers only to Administrative Status object, that is, the message flow is left unmodified for both LSP set-up and deletion. Moreover a new Error Value is defined to identify the failure of a Handover procedure. Caviglia, et al. Expires January 28, 2010 [Page 4] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 Following paragraphs give detailed description of defined "MP to CP handover" and "CP to MP handover" procedures, based on the usage a newly define bit called H bit. MP to CP handover procedure foreseen two different methods for retrieving required information. The primary one consists on receiving the full Explicit Route Object (ERO) from the MP while the alternative one is described in Section 5. Please note that if the primary method is used the labels SHOULD be included in the ERO and for bidirectional LSPs both upstream and downstream labels SHOULD be included. Per Section 5.1.1. of [RFC3473], the labels are indicated on an output basis. As described, this means that the labels are used by the upstream node to create the LABEL_SET object and, for bidirectional LSPs, UPSTREAM_LABEL object used in the outgoing Path message. 4.1. MP to CP handover: LSP Ownership Transfer From Management Plane To Control Plane The MP to CP handover procedure MUST create an RSVP-TE session along the path of the LSP to be moved from MP to CP, associating it to the existing cross-connected resources owned by the MP (e.g. lambdas, time slots or reserved bandwidth) and at the same time transferring their ownership to the CP. A standard RSVP-TE signaling flow MUST be used to inform nodes about the ownership handover request. Such flow MUST be tagged with a newly introduced flag, here named H bit and described in Section 7.1, that is set in the Administrative Status Object ([RFC3471] and [RFC3473]) of RSVP-TE messages. The H bit MUST be set in order to discriminate the handover procedure from normal, DP affecting, LSP setup/release procedure. The DP MUST NOT be affected from the handover procedure. The ingress node MUST send a Path message in the downstream direction with the H and R ([RFC3471]) bit set. Upon receiving a Path Message containing an Administrative Status Object with the H bit set, each node MUST check if there is a local Path State matching the MP to CP Handover request. If no local Path State exists, the node MUST confirm that there is an existing DP state that corresponds to the Path message. In case such DP state exists (failure cases are defined in the next sections), local Path state MUST be installed. The H bit MUST be stored in the local Path state. After propagating a Path message with the H bit set, a node MUST wait for a Resv message including Administrative Status Object with H bit set. After the ingress node receives it, the actual migration of LSP Caviglia, et al. Expires January 28, 2010 [Page 5] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 information is complete, the LSP is left completely under control of RSVP-TE within Control Plane. If the Resv message is not received by the expiration of a timer (called Expiration timer in the following) set by the ingress LER, the handover procedure is aborted, that is, a PathTear message MUST be sent in the downstream direction. In order to complete the Handover process the ingress node MUST send a Path message with the H bit cleared (set to zero) upon receipt of a corresponding Resv message. The R bit SHOULD NOT be set in this message. Downstream nodes MUST clear their local "Handover" state based on a received Path message with the H bit cleared. This means that once a downstream node processes a Path message with the cleared H bit, any state related to the former MP ownership of the LSP is lost. Normal ResvConf process occurs as normal. The handover procedure does not modify the Confirmation procedure. In case the path of the LSP is not fully passed to the ingress LER, each node can determine the next hop looking at its data plane and exploit the similarity between the MP to CP Handover procedure and the Restart Procedure. Please refer to Section 5. 4.2. MP to CP Handover Procedure Failure Handling In case of MP to CP Procedure, two different failure scenarios can happen: Path Failure and Resv Failure. Moreover, each failure can be due to two different causes: DP failure or Communication Failure. In any case the LSP ownership MUST be immediately roll backed to the one previous to the handover procedure. A section for each combination will be analyzed in the following. 4.2.1. MP to CP Handover Failure - Path Failure 4.2.1.1. MP to CP Handover Failure - Path message and Data Plane Failure In this paragraph we will analyze the case where the handover procedure fails during the Path message processing. Caviglia, et al. Expires January 28, 2010 [Page 6] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 | Path | | | |--------------->| Path | | | |---------------X| | | | | | | PathErr | | | |<---------------| | | | | | | Ingress LER LSR A LSR B Egress LER MP2CP - Path Msg and DP Failure If an error occurs in an LSR or a LER, the last node that has received the Path message MUST send a PathErr message in the upstream direction and the handover procedure is aborted. The PathErr message SHOULD have the Path_State_Removed flag set. Nodes receiving a PathErr message MUST follow standard PathErr message processing with the exception that when their local state indicates that a Handover is in progress (based on the H bit in the Path message) the associated DP resources MUST NOT be impacted during such processing. 4.2.1.2. MP to CP Handover Failure - Path message and Communication failure Other possible scenarios are shown in the following pictures and consist on inability to reach a node along the path of the LSP. The below scenario postulates the usage of a reliable message delivery based on the mechanism defined in [RFC2961]. | Path | | | |--------------->| Path | | | |---------------X| | | |---------------X| | | | ... | | | |---------------X| | | | | | Ingress LER LSR A LSR B Egress LER MP2CP - Path Msg and Communication Failure (reliable delivery) The Path message sent from LSR A towards LSR B is lost or does not reach the destination for any reason. As a reliable delivery mechanism is implemented, LSR A retransmits the Path message for a configurable number of times and if no ack is received the handover Caviglia, et al. Expires January 28, 2010 [Page 7] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 procedure will be aborted (via the Expiration timer). In the next scenario RSVP-TE messages are sent without reliable message delivery, that is, no [RFC2961] MessageID procedure is used. | Path | | | |--------------->| Path | | | |----------X | | | | | | |-TIMER EXPIRES--| | | | Path Tear | | | |--------------->| | | | | | | Ingress LER LSR A LSR B Egress LER MP2CP - Path Msg and Communication Failure (no reliable delivery) If the Resv message is not received by the expiration of the Expiration timer the handover procedure is aborted as described in Section 4.1. 4.2.2. MP to CP Handover Failure - Resv Error 4.2.2.1. MP to CP Handover Failure - Resv Error and Data Plane failure In case a failure occurs during the Resv message processing, the node MUST send a PathErr message in the upstream direction. The PathErr message is constructed and processed as defined above in Section 4.2.1.1. The failure detection node MUST also send a PathTear message downstream. The PathTear message is constructed and processed as defined above in Section 4.2.1.1. | Path | Path | Path | |--------------->|--------------->|--------------->| | | | Resv | | | Resv |<---------------| | | X---------| | | PathErr | PathTear | PathTear | |<---------------|--------------->|--------------->| | | | | Ingress LER LSR A LSR B Egress LER MP2CP - Resv Error and DP Failure Caviglia, et al. Expires January 28, 2010 [Page 8] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 In the case shown in the above picture, the failure occurs in LSR A. A PathTear message is sent towards B and a PathErr message is sent in the upstream direction. The PathErr and PathTear messages remove the Path state established by the Path messages along the nodes of the LSP and abort the handover procedure. Please note that the failure occurred after the handover procedure was successfully completed in LSR B, but Handover state will still be maintained locally as, per Section 4.1, a Path message with the H bit clear will have not yet been sent or received. 4.2.2.2. MP to CP Handover Failure - Resv Error and Communication failure In case a Resv message cannot reach one or more of the upstream nodes, the procedure is quite similar to the one previously seen about the Path message. Even in this case it is possible to distinguish two different scenarios. In the first scenario we consider the utilization of a reliable message delivery based on the mechanism defined in [RFC2961]. After a correct forwarding of the Path message along the nodes of the LSP, the Egress LSR sends a Resv message in the opposite direction. It might happen that the Resv message does not reach the ingress LER or an LSR, say LSR A. LSR B MUST send a Resv message again for a configurable number of times and then, if the delivery does not succeed, the adoption procedure will be aborted (via the Expiration timer). | Path | Path | Path | |--------------->|--------------->|--------------->| | | | Resv | | | Resv |<---------------| | | X---------| | | | X---------| | | | ... | | | | X---------| | | | | | Ingress LER LSR A LSR B Egress LER MP2CP - Resv Error and Communication Failure (reliable delivery) Considering that the Resv message did not manage to reach LSR A, it is highly probable that the PathErr would fail too. Due to this fact, the Expiration timer is used on the Ingress LER after sending Caviglia, et al. Expires January 28, 2010 [Page 9] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 the path and on LSR A after forwarding it. When the timer expires, if no Resv or PathErr message is received, the handover procedure is aborted as described in Section 4.1 and the LSP ownership returned to the Management Plane. The following picture, on the other hand, shows the scenario in which no reliable delivery mechanism is implemented. | Path | Path | Path | |--------------->|--------------->|--------------->| | | | Resv | | | Resv |<---------------| | | X---------| | |-TIMER EXPIRES--| | | | Path Tear | Path Tear | Path Tear | |--------------->|--------------->|--------------->| | | | | Ingress LER LSR A LSR B Egress LER MP2CP - Resv Error and Communication Failure (no reliable delivery) If non Resv message is received before the Expiration timer expires, the ingress LER follows the same procedure defined in Section 4.1. 4.2.2.3. MP to CP Handover Failure - Node Graceful Restart In case one of the nodes restarts and graceful restart is enabled then one of the following scenarios will happen. Case I Restart timer is not infinite. In the sequence diagram below, assume LSR A restarts. In case the ingress LER does not receive the Resv message in time it MUST abort the handover process by generating a PathTear message downstream. Also, if LSR A does not complete the restart process within the restart time interval then LSR B MUST start tearing down all LSPs between LSR A and LSR B and this includes the LSP that is being used to carry out the handover of MP resources to CP. LSP B MUST generate a PathTear message downstream and a PathErr message upstream. Both LSR B and the egress LER MUST NOT release the DP resources because in both nodes the H bit is set in the local Path state. Caviglia, et al. Expires January 28, 2010 [Page 10] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 | Path | Path | Path | |--------------->|--------------->|--------------->| | | | Resv | | | Resv |<---------------| | X X---------| | | PathTear | | |-------X Restart Timer | | Expires | | PathErr | PathTear | | X--------|--------------->| | | | | X | | | | | | Ingress LER LSR A LSR B Egress LER MP2CP - Node graceful restart - Case I Case II Restart timer is infinite. The sequence is quite similar to the previous one. In this sequence the restart timer will not expire in LSR B since it is run infinitely. Instead after LSR A restarts LSR B MUST start the recovery timer. The recovery timer will expire since there will be no Path message with the RECOVERY LABEL received from LSR A given the ingress node had already removed the local Path state after it aborts the handover process. Thus LSR B MUST tear-down the specific LSP that is being used to convert the MP resources to CP by generating a PathTear message downstream and PathErr message upstream. Similarly to the previous case both LSR B and the egress LER MUST NOT release the DP resources because the H bit is set in the local Path state. Caviglia, et al. Expires January 28, 2010 [Page 11] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 | Path | Path | Path | |--------------->|--------------->|--------------->| | | | Resv | | | Resv |<---------------| | X X---------| | | PathTear | | |-------X | | | | | | X | | | | | | | | Recovery Timer | | | Expires | | PathErr | PathErr | PathTear | |<---------------|<---------------|--------------->| | | | | Ingress LER LSR A LSR B Egress LER MP2CP - Node graceful restart - Case II Case III Ingress LER did not abort the handover process. Once LSR A restarts the ingress LER MUST re-generate the Path message with the H bit set. When LSR B receives the Path message it MAY generate a PathErr since the RECOVERY LABEL may not be present. The reason is LSR A may not have the label. Similarly LSR B and egress LER MUST NOT release the DP resources since the H bit is set. | Path | Path | Path | |--------------->|--------------->|--------------->| | | | Resv | | | Resv |<---------------| | X X---------| | | | | | X | | | | | | | Path | Path | | |--------------->|--------------->| | | PathErr | PathErr | PathTear | |<---------------|<---------------|--------------->| | | | | Ingress LER LSR A LSR B Egress LER MP2CP - Node graceful restart - Case III Caviglia, et al. Expires January 28, 2010 [Page 12] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 4.3. CP to MP handover : LSP Ownership Transfer From Control Plane To Management Plane Let's now consider the case of LSP Ownership Transfer From Control Plane To Management Plane. Also in this sections we will analyze the handover procedure success and failure. The scenario is still a DP connection between two nodes acting as ingress and egress for a LSP, but in this case the CP has the ownership and control of the LSP. The CP to MP handover procedure MUST delete the existing RSVP-TE session information and MUST NOT affect the cross-connected resources, but just move their ownership to the MP. In other words, after LSP ownership transfer from CP to MP, the LSP is no longer under control of RSVP-TE, which is no more able to "see" the LSP itself. The CP to MP handover procedure MUST be a standard LSP deletion procedure as described in Section 7.2.1 of [RFC3473]. The procedure is initiated at the ingress node of the LSP by a MP entity. Ingress node and MP exchange the relevant information for this task and then propagate it over CP by means of RSVP-TE tear down signaling as described below. The ingress node MUST send a Path message in the downstream direction with Handover and Reflect bits set in the Admin Status Object. No action is taken over the DP and transit LSRs must forward such message towards the egress node. All of the nodes MUST keep track of the procedure storing the H and R bits in their local Path and Resv states. Then every node waits for the H bit to be received within the related Resv message. After the Resv message is received by the ingress LER, it MUST send a PathTear message in order to clear the whole LSP information recorded on the RSVP-TE data structures of the nodes. Downstream nodes processing a PathTear message which follows a Path message with the H bit set, MUST NOT remove any associated data plane state. In other words, a normal LSP tear down signaling is exchanged between nodes traversed by the LSP, but H bit set in the Path message indicates that no DP action has to correspond to CP signaling. 4.4. CP to MP Handover Procedure Failure Failures during CP to MP handover procedure MUST be managed at signaling level as in normal LSP tear down procedure. The only difference is the H bit set in Administrative Status Object inside Path message which MUST be read by receiving node and imposes that no action has to be made over DP resource whose corresponding Control Plane record is involved in handover procedure. Caviglia, et al. Expires January 28, 2010 [Page 13] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 5. Alternative Way Of Retrieving Information Needed For MP To CP Handover An alternative way of getting the LSP related information required for the MP to CP handover is also defined in this draft. The rationale behind this way is that only a minimal set of information is handed over from MP to CP at LSPs Ingress node. Instead of collecting within MP all the LSP relevant information down to the Label level, formatting it to an ERO and passing it to CP, as in previously described solution, it is possible to start with a minimum amount of information. At the ingress node, the information needed to specify the LSP is the outgoing interface ID, upstream label and downstream label of this interface and the egress node ID. The remaining information about an existing LSP can then be collected hop by hop, as the signalling is going on, by looking up the cross- connection table in DP at each node along the LSP path. Starting from the information available at ingress LER about the outgoing interface ID of that ingress node, the incoming interface ID of next hop can be found by looking up the link resource table/ database in the LER itself. The Path message is hence built with the LABEL_SET Object ([RFC3473]) and the UPSTREAM_LABEL Object ([RFC3473]), where the upstream label and downstream label of ingress outgoing interface of the LSP are included in these two objects. In addition to above mentioned objects, the Path message MUST include the Administrative Status Object with H bit set, as already defined in previous chapters for the detailed ERO based way of proceeding. Such handover Path is sent to the incoming interface of next hop. When this Path message reaches the second node along the LSP path, the information about incoming interface ID and the upstream and downstream labels of this interface is extracted from it and it is used to find next hop outgoing interface ID and the upstream/downstream labels by looking up the DP cross-connection table. After having determined in this way the parameters describing the LSPs next hop, the outgoing Path message to be sent is built replacing the LABEL_SET Object and UPSTREAM_LABEL Object content with the looked-up values of upstream and downstream labels. By repeating this procedure for each transit node along the LSP path, it is possible to make the handover Path message reach the egress node, exactly following the LSP that is in place over DP. The ERO MAY in this case be included in the Path message as an optional object, and MAY be filled with the LSP relevant information down to either the port level with interface ID or the Label level with upstream and downstream labels. The ERO can be used to check the Caviglia, et al. Expires January 28, 2010 [Page 14] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 consistency of resource in DP down to the port level or label level at each intermediate node along the LSP path. Where the DP path continues beyond the egress, by indicating the Egress label at the head-end of an LSP, the traffic can be directed to the right destination. The GMPLS Signaling Procedure for Egress Control is described in [RFC4003] 6. RSVP Message Formats This memo does not introduce any modification in RSVP messages object composition. 7. Objects Modification The modifications required concern two RSVP Objects: the Administrative Status and the Error Spec Object. 7.1. Administrative Status Object This memo introduces a new flag into the Administrative Status object. The Admin_Status Object is defined in [RFC3473]. This document uses the H bit of the Admin_Status object. The bit is bit number (TBD by IANA). The format of the Admin_Status Object is: 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 | Class-Num(196)| C-Type (1) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |R| Reserved |H|L|I|C|T|A|D| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The different flags are defined as follows: - Reflect (R): 1 bit - Defined in [RFC3471] - Handover (H): 1bit When set, the H bit indicates that a Handover procedure for the transfer of LSP ownership between Management and Control Planes is ongoing. - Lockout (L): 1 bit - Defined in [RFC4872] - Inhibit Alarm Communication (I): 1 bit - Defined in [RFC4783] Caviglia, et al. Expires January 28, 2010 [Page 15] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 - Call Control (C): 1 bit - Defined in [RFC3471] - Testing (T): 1 bit - Defined in [RFC3471] - Administratively down (A): 1 bit - Defined in [RFC4974] - Deletion in progress (D): 1 bit - Defined in [RFC3471] 7.2. Error Spec Object It is possible that a failure, such as the loss of DCN connection or the restart of a node, occurs during the LSP ownership handing over. In this case the LSP handover is interrupted and the ownership of the LSP moved back to the Plane it belonged to. It is important that the transaction failure does not affect the DP. The LSP is kept in place and no traffic hit occurs. The failure is signaled by PathErr in the upstream direction and PathTear Messages in the downstream direction. The PathErr messages include an Error_Spec_Object specifying the causes of the failure. This memo introduces a new Error Code (with different Error Values) into the Error_Spec Object, defined in [RFC2205]. The defined Error Code is "Handover Procedure Failure", and its value is (TBD by IANA)(33). For this Error Code the following Error Values are defined: 1 = Cross-connection mismatch 2 = DCN error 3 = Other failure 8. Compatibility The main requirement for Handover procedure to work is that all nodes along the path MUST support the extension defined in this draft. In case a node does not support the Handover procedure, the upstream node along the path MUST send a PathErr message in the upstream direction including an Error_Spec_Object specifying the causes of the failure. 9. Acknowledgments We wish to thank Adrian Farrel and Lou Berger for their assistance Caviglia, et al. Expires January 28, 2010 [Page 16] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 and precious advices to prepare this draft for publication. We also wish to thank Nicola Ciulli, that contributed to initial stage of this draft. 10. Contributors Shan Zhu Fujitsu Network Communications Inc. 2801 Telecom Parkway, Richardson, Texas 75082 USA Email: Shan.Zhu@us.fujitsu.com Tel: +1-972-479-2041 Igor Bryskin ADVA Optical Networking Inc 7926 Jones Branch Drive Suite 615 McLean, VA - 22102 Email: ibryskin@advaoptical.com Lou Berger LabN Consulting, LLC Phone: +1 301 468 9228 EMail: lberger@labn.net 11. Security Considerations The procedures described in this document rely completely on RSVP-TE messages and mechanism. The use of H bit set in Admin Status Object basically informs the receiving entity that no operations are to be done over DP as consequence of such special signaling flow. Using specially flagged signaling messages we want to limit the function of setup and tear down messages to CP, making them not effective over related DP resource usage. So, no additional or special issues are arisen by adopting this procedure, that aren't already brought up by the use of the same messages, without H bit setting, for LSP control. For RSVP-TE Security please refer to [RFC3473]. 12. IANA Considerations IANA has been asked to manage the bit allocations for the Administrative Status object ([RFC3473]). This document requires the Caviglia, et al. Expires January 28, 2010 [Page 17] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 allocation of the Handover bit: the H bit. IANA is requested to allocate a bit for this purpose. 13. References 13.1. Normative References [RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 1997. [RFC2961] Berger, L., Gan, D., Swallow, G., Pan, P., Tommasi, F., and S. Molendini, "RSVP Refresh Overhead Reduction Extensions", RFC 2961, April 2001. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC4003] Berger, L., "GMPLS Signaling Procedure for Egress Control", RFC 4003, February 2005. [RFC4974] Papadimitriou, D. and A. Farrel, "Generalized MPLS (GMPLS) RSVP-TE Signaling Extensions in Support of Calls", RFC 4974, August 2007. 13.2. Informational References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003. [RFC4783] Berger, L., "GMPLS - Communication of Alarm Information", RFC 4783, December 2006. [RFC4872] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE Extensions in Support of End-to-End Generalized Multi- Protocol Label Switching (GMPLS) Recovery", RFC 4872, May 2007. [RFC5493] Caviglia, D., Bramanti, D., Li, D., and D. McDysan, "Requirements for the Conversion between Permanent Connections and Switched Connections in a Generalized Multiprotocol Label Switching (GMPLS) Network", RFC 5493, Caviglia, et al. Expires January 28, 2010 [Page 18] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 April 2009. Authors' Addresses Diego Caviglia Ericsson Via A. Negrone 1/A Genova - Sestri Ponente Italy Email: diego.caviglia@ericsson.com Daniele Ceccarelli Ericsson Via A. Negrone 1/A Genova - Sestri Ponente Italy Email: daniele.ceccarelli@ericsson.com Dino Bramanti Ericsson Via Moruzzi 1 C/O Area Ricerca CNR Pisa Italy Email: dino.bramanti@ericsson.com Dan Li Huawei Technologies F3-5-B R&D Center, Huawei Base Shenzhen 518129 P.R.China Email: danli@huawei.com Caviglia, et al. Expires January 28, 2010 [Page 19] Internet-Draft RSVP-TE Ext for MP2CP LSP Handover July 2009 Snigdho Bardalai Fujitsu Network 2801 Telecom Parkway Richrdson, Texas 75082 USA Email: Snigdho.Bardalai@us.fujitsu.com Caviglia, et al. Expires January 28, 2010 [Page 20]