--- 1/draft-ietf-roll-efficient-npdao-02.txt 2018-03-29 20:13:26.932830362 -0700 +++ 2/draft-ietf-roll-efficient-npdao-03.txt 2018-03-29 20:13:26.968831228 -0700 @@ -1,98 +1,100 @@ ROLL R. Jadhav, Ed. Internet-Draft Huawei Intended status: Standards Track P. Thubert -Expires: September 22, 2018 Cisco +Expires: September 30, 2018 Cisco R. Sahoo Z. Cao Huawei - March 21, 2018 + March 29, 2018 - No-Path DAO modifications - draft-ietf-roll-efficient-npdao-02 + Efficient Route Invalidation + draft-ietf-roll-efficient-npdao-03 Abstract This document describes the problems associated with the use of No- - Path DAO messaging in RPL and a signaling changes to improve route + Path DAO messaging in RPL and signaling changes to improve route invalidation efficiency. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. 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 https://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 September 22, 2018. + This Internet-Draft will expire on September 30, 2018. Copyright Notice Copyright (c) 2018 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 (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents - 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Language and Terminology . . . . . . . . . . 3 - 1.2. Current No-Path DAO messaging . . . . . . . . . . . . . . 3 + 1.2. Current No-Path DAO messaging . . . . . . . . . . . . . . 4 1.3. Cases when No-Path DAO may be used . . . . . . . . . . . 4 1.4. Why No-Path DAO is important? . . . . . . . . . . . . . . 5 - 2. Problems with current No-Path DAO messaging . . . . . . . . 5 - 2.1. Lost NP-DAO due to link break to the previous parent . . 5 + 2. Problems with current No-Path DAO messaging . . . . . 5 + 2.1. Lost NPDAO due to link break to the previous parent . . . 5 2.2. Invalidate routes to dependent nodes of the switching - node . . . . . . . . . . . . . . . . . . . . . . . . . . 5 + node . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3. Route downtime caused by asynchronous operation of NPDAO and DAO . . . . . . . . . . . . . . . . . . . . . . 6 3. Requirements for the No-Path DAO Optimization . . . . . . . . 6 - 3.1. Req#1: Tolerant to the link failures to the previous + 3.1. Req#1: Tolerant to link failures to the previous parents . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.2. Req#2: Dependent nodes route invalidation on parent switching . . . . . . . . . . . . . . . . . . . . . . . . 6 - 3.3. Req#3: No impact on traffic while NP-DAO operation in + 3.3. Req#3: No impact on traffic while NPDAO operation in progress . . . . . . . . . . . . . . . . . . . . . . . . 7 4. Proposed changes to RPL signaling . . . . . . . . . . . . . . 7 - 4.1. Change in NPDAO semantics . . . . . . . . . . . . . . . . 7 + 4.1. Change in RPL route invalidation semantics . . . . . . . 7 4.2. DAO message format changes . . . . . . . . . . . . . . . 7 4.3. Destination Cleanup Object (DCO) . . . . . . . . . . . . 8 - 4.3.1. DCO Options . . . . . . . . . . . . . . . . . . . . . 10 - 4.3.2. Path Sequence number in the DCO . . . . . . . . . . . 10 - 4.3.3. Destination Cleanup Option Acknowledgement (DCO-ACK) 10 - 4.4. Example messaging . . . . . . . . . . . . . . . . . . . . 11 - 4.5. Other considerations . . . . . . . . . . . . . . . . . . 12 - 4.5.1. Dependent Nodes invalidation . . . . . . . . . . . . 12 - 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 - 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 - 7. Security Considerations . . . . . . . . . . . . . . . . . . . 13 - 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 + 4.3.1. Secure DCO . . . . . . . . . . . . . . . . . . . . . 10 + 4.3.2. DCO Options . . . . . . . . . . . . . . . . . . . . . 10 + 4.3.3. Path Sequence number in the DCO . . . . . . . . . . . 10 + 4.3.4. Destination Cleanup Option Acknowledgement (DCO-ACK) 10 + 4.3.5. Secure DCO-ACK . . . . . . . . . . . . . . . . . . . 11 + 4.4. Other considerations . . . . . . . . . . . . . . . . . . 11 + 4.4.1. Dependent Nodes invalidation . . . . . . . . . . . . 11 + 4.4.2. NPDAO and DCO in the same network . . . . . . . . . . 12 + 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12 + 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 8.1. Normative References . . . . . . . . . . . . . . . . . . 13 - 8.2. Informative References . . . . . . . . . . . . . . . . . 14 - Appendix A. Additional Stuff . . . . . . . . . . . . . . . . . . 14 + 8.2. Informative References . . . . . . . . . . . . . . . . . 13 + Appendix A. Example DCO Messaging . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 1. Introduction RPL [RFC6550] specifies a proactive distance-vector based routing scheme. The specification has an optional messaging in the form of DAO messages using which the 6LBR can learn route towards any of the nodes. In storing mode, DAO messages would result in routing entries been created on all intermediate hops from the node's parent all the way towards the 6LBR. @@ -122,22 +124,22 @@ The document only caters to the RPL's storing mode of operation (MOP). The non-storing MOP does not require use of NPDAO for route invalidation since routing entries are not maintained on 6LRs. Common Ancestor node: 6LR node which is the first common node on the old and new path for the child node. NPDAO: No-Path DAO. A DAO message which has target with lifetime 0. - DCO: A new RPL control message type defined by this specification and - stands for Destination Cleanup Object. + DCO: Destination Cleanup Object, A new RPL control message type + defined by this draft. Regular DAO: A DAO message with non-zero lifetime. This document also uses terminology described in [RFC6550]. 1.2. Current No-Path DAO messaging RPL introduced No-Path DAO messaging in the storing mode so that the node switching its current parent can inform its parents and ancestors to invalidate the existing route. Subsequently parents or @@ -207,33 +209,33 @@ necessary to have efficient route invalidation mechanism. Also note that a single parent switch may result in a "sub-tree" switching from one parent to another. Thus the route invalidation needs to be done on behalf of the sub-tree and not the switching node alone. In the above example, when Node (D) switches parent, the route invalidation needs to be done for (D), (E) and (F). Thus without efficient route invalidation, a 6LR may have to hold a lot of unwanted route entries. 2. Problems with current No-Path DAO messaging -2.1. Lost NP-DAO due to link break to the previous parent +2.1. Lost NPDAO due to link break to the previous parent When a node switches its parent, the NPDAO is to be sent via its previous parent and a regular DAO via its new parent. In cases where the node switches its parent because of transient or permanent parent link/node failure then the NPDAO message is bound to fail. RPL assumes communication link with the previous parent for No-Path DAO messaging. RPL allows use of route lifetime to remove unwanted routes in case the routes could not be refreshed. But route lifetimes in case of LLNs could be substantially high and thus the route entries would be - stuck for long. + stuck for longer times. 2.2. Invalidate routes to dependent nodes of the switching node No-path DAO is sent by the node who has switched the parent but it does not work for the dependent child nodes below it. The specification does not specify how route invalidation will work for sub-childs, resulting in stale routing entries on behalf of the sub- childs on the previous route. The only way for 6LR to invalidate the route entries for dependent nodes would be to use route lifetime expiry which could be substantially high for LLNs. @@ -254,65 +256,58 @@ via the new path gets lost on the way. This may result in route downtime thus impacting downward traffic for the switching node. In the example topology, consider Node (D) switches from parent (B) to (C) because the metrics of the path via (C) are better. Note that the previous path via (B) may still be available (albeit at relatively bad metrics). An NPDAO sent from previous route may invalidate the existing route whereas there is no way to determine whether the new DAO has successfully updated the route entries on the new path. - An implementation technique to avoid this problem is to further delay - the route invalidation by a fixed time interval after receiving an - NPDAO, considering the time taken for the new path to be established. - Coming up with such a time interval is tricky since the new route may - also not be available and it may subsequently require more parent - switches to establish a new path. - 3. Requirements for the No-Path DAO Optimization -3.1. Req#1: Tolerant to the link failures to the previous parents +3.1. Req#1: Tolerant to link failures to the previous parents - When the switching node send the NP-DAO message to the previous + When the switching node send the NPDAO message to the previous parent, it is normal that the link to the previous parent is prone to - failure. Therefore, it is required that the NP-DAO message MUST be + failure. Therefore, it is required that the NPDAO message MUST be tolerant to the link failure during the switching. 3.2. Req#2: Dependent nodes route invalidation on parent switching - While switching the parent node and sending NP-DAO message, it is + While switching the parent node and sending NPDAO message, it is required that the routing entries to the dependent nodes of the switching node will be updated accordingly on the previous parents and other relevant upstream nodes. -3.3. Req#3: No impact on traffic while NP-DAO operation in progress +3.3. Req#3: No impact on traffic while NPDAO operation in progress - While sending the NP-DAO and DAO messages, it is possible that the - NP-DAO successfully invalidates the previous path, while the newly + While sending the NPDAO and DAO messages, it is possible that the + NPDAO successfully invalidates the previous path, while the newly sent DAO gets lost (new path not set up successfully). This will result into downstream unreachability to the current switching node. - Therefore, it is desirable that the NP-DAO is synchronized with the + Therefore, it is desirable that the NPDAO is synchronized with the DAO to avoid the risk of route downtime. 4. Proposed changes to RPL signaling -4.1. Change in NPDAO semantics +4.1. Change in RPL route invalidation semantics As described in Section 1.2, the NPDAO originates at the node switching the parent and traverses upstream towards the root. In - order to solve the problems as mentioned in Section 2, the draft - proposes to add new pro-active route invalidation message called as - "Destination Cleanup Object" (DCO) that originates at a common - ancestor node between the new and old path. The trigger for the - common ancestor node to generate this DCO is the change in the next - hop for the target on reception of an update message in the form of - regular DAO for the target. + order to solve the problems as mentioned in Section 2, the draft adds + new pro-active route invalidation message called as "Destination + Cleanup Object" (DCO) that originates at a common ancestor node + between the new and old path. The trigger for the common ancestor + node to generate this DCO is the change in the next hop for the + target on reception of an update message in the form of regular DAO + for the target. In the Figure 1, when node D decides to switch the path from B to C, it sends a regular DAO to node C with reachability information containing target as address of D and a incremented path sequence number. Node C will update the routing table based on the reachability information in DAO and in turn generate another DAO with the same reachability information and forward it to H. Node H also follows the same procedure as Node C and forwards it to node A. When node A receives the regular DAO, it finds that it already has a routing table entry on behalf of the target address of node D. It @@ -356,20 +351,26 @@ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: Updated Transit Information Option (New I flag added) I (Invalidate previous route) bit: 1 bit flag. The 'I' flag is set by the target node to indicate that it wishes to invalidate the previous route by a common ancestor node between the two paths. + The common ancestor node SHOULD generate a DCO message in response to + this I-bit when it sees that the routing adjacencies have changed for + the target. I-bit governs the ownership of the DCO message in a way + that the target node is still in control of its own route + invalidation. + 4.3. Destination Cleanup Object (DCO) A new ICMPv6 RPL control message type is defined by this specification called as "Destination Cleanup Object" (DCO), which is used for proactive cleanup of state and routing information held on behalf of the target node by 6LRs. The DCO message always traverses downstream and cleans up route information and other state information associated with the given target. 0 1 2 3 @@ -407,51 +408,56 @@ by the sender and MUST be ignored by the receiver. DCOSequence: Incremented at each unique DCO message from a node and echoed in the DCO-ACK message. DODAGID (optional): 128-bit unsigned integer set by a DODAG root that uniquely identifies a DODAG. This field is only present when the 'D' flag is set. This field is typically only present when a local RPLInstanceID is in use, in order to identify the DODAGID that is associated with the RPLInstanceID. When a global RPLInstanceID is in - use, this field need not be present. Unassigned bits of the DAO Base + use, this field need not be present. Unassigned bits of the DCO Base are reserved. They MUST be set to zero on transmission and MUST be ignored on reception. -4.3.1. DCO Options +4.3.1. Secure DCO + + A Secure DCO message follows the format in [RFC6550] figure 7, where + the base message format is the DCO message shown in Figure 3. + +4.3.2. DCO Options The DCO message MAY carry valid options. This specification allows for the DCO message to carry the following options: 0x00 Pad1 0x01 PadN 0x05 RPL Target 0x06 Transit Information 0x09 RPL Target Descriptor The DCO carries a Target option and an associated Transit Information option with a lifetime of 0x00000000 to indicate a loss of reachability to that Target. -4.3.2. Path Sequence number in the DCO +4.3.3. Path Sequence number in the DCO A DCO message may contain a Path Sequence in the transit information option to identify the freshness of the DCO message. The Path - Sequence in the DCO and should use the same Path Sequence number - present in the regular DAO message when the DCO is generated in - response to DAO message. + Sequence in the DCO MUST use the same Path Sequence number present in + the regular DAO message when the DCO is generated in response to DAO + message. -4.3.3. Destination Cleanup Option Acknowledgement (DCO-ACK) +4.3.4. Destination Cleanup Option Acknowledgement (DCO-ACK) - The DCO-ACK message is sent as a unicast packet by a DCO recipient in - response to a unicast DCO message. + The DCO-ACK message may be sent as a unicast packet by a DCO + recipient in response to a unicast DCO message. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | RPLInstanceID |D| Reserved | DCOSequence | Status | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + DODAGID(optional) + @@ -476,174 +482,161 @@ Status: Indicates the completion. Status 0 is defined as unqualified acceptance in this specification. The remaining status values are reserved as rejection codes. DODAGID (optional): 128-bit unsigned integer set by a DODAG root that uniquely identifies a DODAG. This field is only present when the 'D' flag is set. This field is typically only present when a local RPLInstanceID is in use, in order to identify the DODAGID that is associated with the RPLInstanceID. When a global RPLInstanceID is in - use, this field need not be present. Unassigned bits of the DAO Base - are reserved. They MUST be set to zero on transmission and MUST be - ignored on reception. - -4.4. Example messaging - - In Figure 1, node (D) switches its parent from (B) to (C). The - sequence of actions is as follows: + use, this field need not be present. Unassigned bits of the DCO-Ack + Base are reserved. They MUST be set to zero on transmission and MUST + be ignored on reception. - 1. Node D switches its parent from node B to node C - 2. D sends a regular DAO(tgt=D,pathseq=x+1,I_flag=1) in the updated - path to C - 3. C checks for routing entry on behalf of D, since it cannot find - an entry on behalf of D it creates a new routing entry and - forwards the reachability information of the target D to H in a - DAO. - 4. Similar to C, node H checks for routing entry on behalf of D, - cannot find an entry and hence creates a new routing entry and - forwards the reachability information of the target D to H in a - DAO. - 5. Node A receives the DAO, and checks for routing entry on behalf - of D. It finds a routing entry but checks that the next hop for - target D is now changed. Node A checks the I_flag and generates - DCO(tgt=D,pathseq=pathseq(DAO)) to previous next hop for target D - which is G. Subsequently, A updates the routing entry and - forwards the reachability information of target D upstream - DAO(tgt=D,pathseq=x+1,I_flag=x) (the I_flag carries no - significance henceforth). - 6. Node G receives the DCO and invalidates routing entry of target D - and forwards the (un)reachability information downstream to B. +4.3.5. Secure DCO-ACK - 7. Similarly, B processes the DCO by invalidating the routing entry - of target D and forwards the (un)reachability information - downstream to D. - 8. D ignores the DCO since the target is itself. - 9. The propagation of the DCO will stop at any node where the node - does not have an routing information associated with the target. - If the routing information is present and the pathseq associated - is not older, then still the DCO is dropped. + A Secure DCO-ACK message follows the format in [RFC6550] figure 7, + where the base message format is the DCO-ACK message shown in + Figure 4. -4.5. Other considerations +4.4. Other considerations -4.5.1. Dependent Nodes invalidation +4.4.1. Dependent Nodes invalidation Current RPL [RFC6550] does not provide a mechanism for route - invalidation for dependent nodes. - - This section describes approaches for invalidating routes of - dependent nodes if the implementation chooses to solve this problem. - The common ancestor node realizes that the paths for dependent nodes - have changed (based on next hop change) when it receives a regular - DAO on behalf of the dependent nodes. Thus dependent nodes route - invalidation can be handled in the same way as the switching node. - Note that there is no way that dependent nodes can set the I_flag in - the DAO message selectively since they are unaware that their parent/ - grand parent node is switching paths. There are two ways to handle - dependent node route invalidation: + invalidation for dependent nodes. This document allows the dependent + nodes invalidation. Dependent nodes will generate their respective + DAOs to update their paths, and the previous route invalidation for + those nodes should work in the similar manner described for switching + node. The dependent node may set the I-bit in the transit + information container as part of regular DAO so as to request + invalidation of previous route from the common ancestor node. - 1. One way to resolve is that the common ancestor does not depend - upon the I_flag to generate the reverse NPDAO. The only factor - it makes the decision will be based on next_hop change for an - existing target to generate the NPDAO. Thus when the switching - nodes and all the below dependent nodes advertise a regular DAO, - the common ancestor node will detect a change in next hop and - generate NPDAO for the same target as in the regular DAO. - 2. Another way is that the nodes always set the I_flag whenever they - send regular DAO. Thus common ancestor will first check whether - I_flag is set and then check whether the next_hop has changed and - subsequently trigger DCO if required. +4.4.2. NPDAO and DCO in the same network - This document recommends the approach in point 2. The advantage with - I_flag is that the generation of downstream NPDAO is still controlled - by the target node and thus is still in control of its own routing - state. + Even with the changed semantics, the current NPDAO mechanism in + [RFC6550] can still be used. There are certain scenarios where + current NPDAO signalling may still be used, for example, when the + route lifetime expiry of the target happens or when the node simply + decides to gracefully terminate the RPL session on graceful node + shutdown. Moreover a deployment can have a mix of nodes supporting + the proposed DCO and the existing NPDAO mechanism. 5. Acknowledgements - We would like to thank Cenk Gundogan, Simon Duquennoy and Pascal - Thubert for their review and comments. + We would like to thank Cenk Gundogan and Simon Duquennoy for their + review and comments. 6. IANA Considerations IANA is requested to allocate new ICMPv6 RPL control codes in RPL [RFC6550] for DCO and DCO-ACK messages. - +------+--------------------------------------------+---------------+ + +------+---------------------------------------------+--------------+ | Code | Description | Reference | - +------+--------------------------------------------+---------------+ - | 0x85 | Destination Cleanup Object | This document | - | 0x86 | Destination Cleanup Object Acknowledgement | This document | - +------+--------------------------------------------+---------------+ + +------+---------------------------------------------+--------------+ + | 0x04 | Destination Cleanup Object | This | + | | | document | + | 0x05 | Destination Cleanup Object Acknowledgement | This | + | | | document | + | 0x84 | Secure Destination Cleanup Object | This | + | | | document | + | 0x85 | Secure Destination Cleanup Object | This | + | | Acknowledgement | document | + +------+---------------------------------------------+--------------+ IANA is requested to allocate bit 18 in the Transit Information Option defined in RPL [RFC6550] section 6.7.8 for Invalidate route 'I' flag. 7. Security Considerations - The secure versions of DCO and DCO-ACK also have to be considered in - the future. The seucrity considerations applicable to DAO, DAO-ACK - messaging in RPL is also applicable here. + This document handles security considerations inline to base RPL. + Secure versions of DCO and DCO-ACK are added similar to other RPL + messages. For general RPL security considerations, see [RFC6550]. 8. References - 8.1. Normative References - [I-D.ietf-6tisch-architecture] - Thubert, P., "An Architecture for IPv6 over the TSCH mode - of IEEE 802.15.4", draft-ietf-6tisch-architecture-13 (work - in progress), November 2017. - [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J., Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur, JP., and R. Alexander, "RPL: IPv6 Routing Protocol for Low-Power and Lossy Networks", RFC 6550, DOI 10.17487/RFC6550, March 2012, . 8.2. Informative References - [CONTIKI] Thingsquare, "Contiki: The Open Source OS for IoT", 2012, - . + [I-D.ietf-6tisch-architecture] + Thubert, P., "An Architecture for IPv6 over the TSCH mode + of IEEE 802.15.4", draft-ietf-6tisch-architecture-13 (work + in progress), November 2017. - [RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC - Text on Security Considerations", BCP 72, RFC 3552, - DOI 10.17487/RFC3552, July 2003, - . +Appendix A. Example DCO Messaging -Appendix A. Additional Stuff + In Figure 1, node (D) switches its parent from (B) to (C). The + sequence of actions is as follows: - This becomes an Appendix. + 1. Node D switches its parent from node B to node C + 2. D sends a regular DAO(tgt=D,pathseq=x+1,I_flag=1) in the updated + path to C + 3. C checks for routing entry on behalf of D, since it cannot find + an entry on behalf of D it creates a new routing entry and + forwards the reachability information of the target D to H in a + DAO. + 4. Similar to C, node H checks for routing entry on behalf of D, + cannot find an entry and hence creates a new routing entry and + forwards the reachability information of the target D to H in a + DAO. + 5. Node A receives the DAO, and checks for routing entry on behalf + of D. It finds a routing entry but checks that the next hop for + target D is now changed. Node A checks the I_flag and generates + DCO(tgt=D,pathseq=pathseq(DAO)) to previous next hop for target D + which is G. Subsequently, A updates the routing entry and + forwards the reachability information of target D upstream + DAO(tgt=D,pathseq=x+1,I_flag=x) (the I_flag carries no + significance henceforth). + 6. Node G receives the DCO and invalidates routing entry of target D + and forwards the (un)reachability information downstream to B. + + 7. Similarly, B processes the DCO by invalidating the routing entry + of target D and forwards the (un)reachability information + downstream to D. + 8. D ignores the DCO since the target is itself. + 9. The propagation of the DCO will stop at any node where the node + does not have an routing information associated with the target. + If the routing information is present and the pathseq associated + is not older, then still the DCO is dropped. Authors' Addresses Rahul Arvind Jadhav (editor) Huawei Kundalahalli Village, Whitefield, Bangalore, Karnataka 560037 India Phone: +91-080-49160700 Email: rahul.ietf@gmail.com Pascal Thubert Cisco Systems, Inc Building D 45 Allee des Ormes - BP1200 MOUGINS - Sophia Antipolis 06254 - FRANCE + France Phone: +33 497 23 26 34 Email: pthubert@cisco.com Rabi Narayan Sahoo Huawei Kundalahalli Village, Whitefield, Bangalore, Karnataka 560037 India