Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for the evolving G.709 Optical Transport Networks Control
draft-ietf-ccamp-gmpls-signaling-g709v3-01
The information below is for an old version of the document.
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This is an older version of an Internet-Draft that was ultimately published as RFC 7139.
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Authors | Daniele Ceccarelli , Fatai Zhang , Guoying Zhang , Khuzema Pithewan , Sergio Belotti | ||
Last updated | 2011-10-25 (Latest revision 2011-10-17) | ||
Replaces | draft-zhang-ccamp-gmpls-evolving-g709 | ||
RFC stream | Internet Engineering Task Force (IETF) | ||
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draft-ietf-ccamp-gmpls-signaling-g709v3-01
Network Working Group Fatai Zhang, Ed. Internet Draft Huawei Category: Standards Track Guoying Zhang CATR Sergio Belotti Alcatel-Lucent D. Ceccarelli Ericsson Khuzema Pithewan Infinera Expires: April 26, 2012 October 26, 2011 Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for the evolving G.709 Optical Transport Networks Control draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt 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 April 26, 2012. Abstract Recent progress in ITU-T Recommendation G.709 standardization has introduced new ODU containers (ODU0, ODU4, ODU2e and ODUflex) and Zhang Expires April 2012 [Page 1] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 enhanced Optical Transport Networking (OTN) flexibility. Several recent documents have proposed ways to modify GMPLS signaling protocols to support these new OTN features. It is important that a single solution is developed for use in GMPLS signaling and routing protocols. This solution must support ODUk multiplexing capabilities, address all of the new features, be acceptable to all equipment vendors, and be extensible considering continued OTN evolution. This document describes the extensions to the Generalized Multi- Protocol Label Switching (GMPLS) signaling to control the evolving Optical Transport Networks (OTN) addressing ODUk multiplexing and new features including ODU0, ODU4, ODU2e and ODUflex. Conventions used in this document 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]. Table of Contents 1. Introduction .................................................. 3 2. Terminology ................................................... 4 3. GMPLS Extensions for the Evolving G.709 - Overview ............ 4 4. Generalized Label Request ..................................... 5 5. Extensions for Traffic Parameters for the Evolving G.709 ...... 5 5.1. Usage of ODUflex(CBR) Traffic Parameter .................. 7 5.2. Usage of ODUflex(GFP) Traffic Parameters ................. 9 6. Generalized Label ............................................. 9 6.1. New definition of ODU Generalized Label ................. 10 6.2. Examples ................................................ 12 6.3. Label Distribution Procedure ............................ 14 6.3.1. Notification on Label Error ........................ 15 6.4. Supporting Virtual Concatenation and Multiplication ..... 15 6.5. Control Plane Backward Compatibility Considerations ..... 16 7. Supporting Multiplexing Hierarchy ............................ 17 7.1. ODU FA-LSP Creation ..................................... 18 8. Security Considerations ...................................... 18 9. IANA Considerations .......................................... 18 10. References .................................................. 19 10.1. Normative References ................................... 19 Zhang Expires April 2012 [Page 2] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 10.2. Informative References ................................. 20 11. Contributors ................................................ 21 12. Authors' Addresses .......................................... 21 13. Acknowledgment .............................................. 24 1. Introduction Generalized Multi-Protocol Label Switching (GMPLS) [RFC3945] extends MPLS to include Layer-2 Switching (L2SC), Time-Division Multiplex (e.g., SONET/SDH, PDH, and ODU), Wavelength (OCh, Lambdas) Switching, and Spatial Switching (e.g., incoming port or fiber to outgoing port or fiber). [RFC3471] presents a functional description of the extensions to Multi-Protocol Label Switching (MPLS) signaling required to support Generalized MPLS. RSVP-TE-specific formats and mechanisms and technology specific details are defined in [RFC3473]. With the evolution and deployment of G.709 technology, it is necessary that appropriate enhanced control technology support be provided for G.709. [RFC4328] describes the control technology details that are specific to foundation G.709 Optical Transport Networks (OTN), as specified in the ITU-T Recommendation G.709 [G709- V1], for ODUk deployments without multiplexing. In addition to increasing need to support ODUk multiplexing, the evolution of OTN has introduced additional containers and new flexibility. For example, ODU0, ODU2e, ODU4 containers and ODUflex are developed in [G709-V3]. In addition, the following issues require consideration: - Support for hitless adjustment of ODUflex, which is to be specified in ITU-T G.hao. - Support for Tributary Port Number. The Tributary Port Number has to be negotiated on each link for flexible assignment of tributary ports to tributary slots in case of LO-ODU over HO- ODU (e.g., ODU2 into ODU3). Therefore, it is clear that [RFC4328] has to be updated or superceded in order to support ODUk multiplexing, as well as other ODU enhancements introduced by evolution of OTN standards. This document updates [RFC4328] extending the G.709 ODUk traffic parameters and also presents a new OTN label format which is very flexible and scalable. Zhang Expires April 2012 [Page 3] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 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. GMPLS Extensions for the Evolving G.709 - Overview New features for the evolving OTN, for example, new ODU0, ODU2e, ODU4 and ODUflex containers are specified in [G709-V3]. The corresponding new signal types are summarized below: - Optical Channel Transport Unit (OTUk): . OTU4 - Optical Channel Data Unit (ODUk): . ODU0 . ODU2e . ODU4 . ODUflex A new Tributary Slot (TS) granularity (i.e., 1.25 Gbps) is also described in [G709-V3]. Thus, there are now two TS granularities for the foundation OTN ODU1, ODU2 and ODU3 containers. The TS granularity at 2.5 Gbps is used on legacy interfaces while the new 1.25 Gbps is used on the new interfaces. In addition to the support of ODUk mapping into OTUk (k = 1, 2, 3, 4), the evolving OTN [G.709-V3] encompasses the multiplexing of ODUj (j = 0, 1, 2, 2e, 3, flex) into an ODUk (k > j), as described in Section 3.1.2 of [OTN-FWK]. Virtual Concatenation (VCAT) of OPUk (OPUk-Xv, k = 1/2/3, X = 1...256) is also supported by [OTN-V3]. Note that VCAT of OPU0 / OPU2e / OPU4 / OPUflex is not supported per [OTN-V3]. [RFC4328] describes GMPLS signaling extensions to support the control for G.709 Optical Transport Networks (OTN) [G709-V1]. However, [RFC4328] needs to be updated because it does not provide the means to signal all the new signal types and related mapping and multiplexing functionalities. Moreover, it supports only the deprecated auto-MSI mode which assumes that the Tributary Port Number is automatically assigned in the transmit direction and not checked in the receive direction. This document extends the G.709 traffic parameters described in [RFC4328] and presents a new flexible and scalable OTN label format. Zhang Expires April 2012 [Page 4] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 Additionally, procedures about Tributary Port Number assignment through control plane are also provided in this document. 4. Generalized Label Request The Generalized Label Request, as described in [RFC3471], carries the LSP Encoding Type, the Switching Type and the Generalized Protocol Identifier (G-PID). [RFC4328] extends the Generalized Label Request, introducing two new code-points for the LSP Encoding Type (i.e., G.709 ODUk (Digital Path) and G.709 Optical Channel) and adding a list of G-PID values in order to accommodate [G709-v1]. This document follows these extensions and a new Switching Type is introduced to indicate the ODUk switching capability [G709-V3] in order to support backward compatibility with [RFC4328], as described in [OTN-FWK]. The new Switching Type (101, TBA by IANA) is defined in [OTN-OSPF]. 5. Extensions for Traffic Parameters for the Evolving G.709 The traffic parameters for G.709 are defined as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | Reserved | NMC/ Tolerance | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NVC | Multiplier (MT) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Bit_Rate | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The Signal Type needs to be extended in order to cover the new Signal Type introduced by the evolving OTN. The new Signal Type values are extended as follows: Value Type ----- ---- 0 Not significant 1 ODU1 (i.e., 2.5 Gbps) 2 ODU2 (i.e., 10 Gbps) 3 ODU3 (i.e., 40 Gbps) Zhang Expires April 2012 [Page 5] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 4 ODU4 (i.e., 100 Gbps) 5 Reserved (for future use) 6 OCh at 2.5 Gbps 7 OCh at 10 Gbps 8 OCh at 40 Gbps 9 OCh at 100 Gbps 10 ODU0 (i.e., 1.25 Gbps) 11 ODU2e (i.e., 10Gbps for FC1200 and GE LAN) 12~19 Reserved (for future use) 20 ODUflex(CBR) (i.e., 1.25*N Gbps) 21 ODUflex(GFP-F), resizable (i.e., 1.25*N Gbps) 22 ODUflex(GFP-F), non resizable (i.e., 1.25*N Gbps) 23~255 Reserved (for future use) NMC/Tolerance: This field is redefined from the original definition in [RFC4328]. NMC field defined in [RFC4328] cannot be fixed value for an end-to- end circuit involving dissimilar OTN link types. For example, ODU2e requires 9 TS on ODU3 and 8 TS on ODU4. Usage of NMC field is deprecated and should be used only with [RFC4328] generalized label format for backwards compatibility reasons. For the new generalized label format as defined in this document this field is interpreted as Tolerance. In case of ODUflex(CBR), the Bit_Rate and Tolerance fields MUST be used together to represent the actual bandwidth of ODUflex, where: - The Bit_Rate field indicates the nominal bit rate of ODUflex(CBR) expressed in bytes per second, encoded as a 32-bit IEEE single- precision floating-point number (referring to [RFC4506] and [IEEE]). The value contained in the Bit Rate field has to keep into account both 239/238 factor and the Transcoding factor. - The Tolerance field indicates the bit rate tolerance (part per million, ppm) of the ODUflex(CBR) encoded as an unsigned integer, which is bounded in 0~100ppm. For example, for an ODUflex(CBR) service with Bit_Rate = 2.5Gbps and Tolerance = 100ppm, the actual bandwidth of the ODUflex is: 2.5Gbps * (1 +/- 100ppm) In case of ODUflex(GFP), the Bit_Rate field is used to indicate the nominal bit rate of the ODUflex(GFP), which implies the number of Zhang Expires April 2012 [Page 6] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 tributary slots requested for the ODUflex(GFP). Since the tolerance of ODUflex(GFP) makes no sense on tributary slot resource reservation, the Tolerance field for ODUflex(GFP) is not necessary and MUST be filled with 0. In case of other ODUk signal types, the Bit_Rate and Tolerance fields are not necessary and MUST be set to 0. The usage of the NVC and Multiplier (MT) fields are the same as [RFC4328]. 5.1. Usage of ODUflex(CBR) Traffic Parameter In case of ODUflex(CBR), the information of Bit_Rate and Tolerance in the ODUflex traffic parameter MUST be used to determine the total number of tributary slots N in the HO ODUk link to be reserved. Here: N = Ceiling of ODUflex(CBR) nominal bit rate * (1 + ODUflex(CBR) bit rate tolerance) --------------------------------------------------------------------- ODTUk.ts nominal bit rate * (1 - HO OPUk bit rate tolerance) In this formula, the ODUflex(CBR) nominal bit rate is the bit rate of the ODUflex(CBR) on the line side, i.e., the client signal bit rate after applying the 239/238 factor (according to clause 7.3 table 7.2 of [G709-V3]) and the transcoding factor T (if needed) on the CBR client. According to clauses 17.7.3, 17.7.4 and 17.7.5 of [G709-V3]: ODUflex(CBR) nominal bit rate = CBR client bit rate * (239/238) / T The ODTUk.ts nominal bit rate is the nominal bit rate of the tributary slot of ODUk, as shown in Table 1 (referring to [G709-V3]). Table 1 - Actual TS bit rate of ODUk (in Gbps) ODUk.ts Minimum Nominal Maximum ---------------------------------------------------------- ODU2.ts 1.249 384 632 1.249 409 620 1.249 434 608 ODU3.ts 1.254 678 635 1.254 703 729 1.254 728 823 ODU4.ts 1.301 683 217 1.301 709 251 1.301 735 285 Note that: Minimum bit rate of ODUTk.ts = ODTUk.ts nominal bit rate * (1 - HO OPUk bit rate tolerance) Zhang Expires April 2012 [Page 7] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 Maximum bit rate of ODTUk.ts = ODTUk.ts nominal bit rate * (1 + HO OPUk bit rate tolerance) Where: HO OPUk bit rate tolerance = 20ppm Therefore, a node receiving a PATH message containing ODUflex(CBR) nominal bit rate and tolerance can allocate precise number of tributary slots and set up the cross-connection for the ODUflex service. Note that for different ODUk, the bit rates of the tributary slots are different, and so the total number of tributary slots to be reserved for the ODUflex(CBR) may not be the same on different HO ODUk links. An example is given below to illustrate the usage of ODUflex(CBR) traffic parameter. As shown in Figure 1, assume there is an ODUflex(CBR) service requesting a bandwidth of (2.5Gbps, +/-100ppm) from node A to node C. In other words, the ODUflex traffic parameters indicate that Signal Type is 20 (ODUflex(CBR)), Bit_Rate is 2.5Gbps and Tolerance is 100ppm. +-----+ +---------+ +-----+ | +-------------+ +-----+ +-------------+ | | +=============+\| ODU |/+=============+ | | +=============+/| flex+-+=============+ | | +-------------+ | |\+=============+ | | +-------------+ +-----+ +-------------+ | | | | | | | | | ....... | | ....... | | | A +-------------+ B +-------------+ C | +-----+ HO ODU4 +---------+ HO ODU2 +-----+ =========: TS occupied by ODUflex ---------: free TS Figure 1 - Example of ODUflex(CBR) Traffic Parameters - On the HO ODU4 link between node A and B: The maximum bit rate of the ODUflex(CBR) equals 2.5Gbps * (1 + 100ppm), and the minimum bit rate of the tributary slot of ODU4 Zhang Expires April 2012 [Page 8] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 equals 1.301 683 217Gbps, so the total number of tributary slots N1 to be reserved on this link is: N1 = ceiling (2.5Gbps * (1 + 100ppm) / 1.301 683 217Gbps) = 2 - On the HO ODU2 link between node B and C: The maximum bit rate of the ODUflex equals 2.5Gbps * (1 + 100ppm), and the minimum bit rate of the tributary slot of ODU2 equals 1.249 384 632Gbps, so the total number of tributary slots N2 to be reserved on this link is: N2 = ceiling (2.5Gbps * (1 + 100ppm) / 1.249 384 632Gbps) = 3 5.2. Usage of ODUflex(GFP) Traffic Parameters [G709-V3-A2] recommends that the ODUflex(GFP) will fill an integral number of tributary slots of the smallest HO ODUk path over which the ODUflex(GFP) may be carried, as shown in Table 2. Table 2 - Recommended ODUflex(GFP) bit rates and tolerance ODU type | Nominal bit-rate | Tolerance --------------------------------+------------------+----------- ODUflex(GFP) of n TS, 1<=n<=8 | n * ODU2.ts | +/-100 ppm ODUflex(GFP) of n TS, 9<=n<=32 | n * ODU3.ts | +/-100 ppm ODUflex(GFP) of n TS, 33<=n<=80 | n * ODU4.ts | +/-100 ppm Accoding to this table, the Bit_Rate field for ODUflex(GFP) MUST equal to one of the 80 values listed below: 1 * ODU2.ts; 2 * ODU2.ts; ...; 8 * ODU2.ts; 9 * ODU3.ts; 10 * ODU3.ts, ...; 32 * ODU3.ts; 33 * ODU4.ts; 34 * ODU4.ts; ...; 80 * ODU4.ts. In this way, the number of required tributary slots for the ODUflex(GFP) (i.e., the value of "n" in Table 2) can be deduced from the Bit_Rate field. 6. Generalized Label [RFC3471] has defined the Generalized Label which extends the traditional label by allowing the representation of not only labels Zhang Expires April 2012 [Page 9] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 which are sent in-band with associated data packets, but also labels which identify time-slots, wavelengths, or space division multiplexed positions. The format of the corresponding RSVP-TE Generalized Label object is defined in the Section 2.3 of [RFC3473]. However, for different technologies, we usually need use specific label rather than the Generalized Label. For example, the label format described in [RFC4606] could be used for SDH/SONET, the label format in [RFC4328] for G.709. 6.1. New definition of ODU Generalized Label In order to be compatible with new types of ODU signal and new types of tributary slot, the following new ODU label format MUST be used: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TPN | Reserved | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Bit Map ......... ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The ODU Generalized Label is used to indicate how the LO ODUj signal is multiplexed into the HO ODUk link. Note that the LO OUDj signal type is indicated by traffic parameters, while the type of HO ODUk link can be figured out locally according to the identifier of the selected interface carried in the IF_ID RSVP_HOP Object. TPN (12 bits): indicates the Tributary Port Number (TPN) for the assigned Tributary Slot(s). - In case of LO ODUj multiplexed into HO ODU1/ODU2/ODU3, only the lower 6 bits of TPN field are significant and the other bits of TPN MUST be set to 0. - In case of LO ODUj multiplexed into HO ODU4, only the lower 7 bits of TPN field are significant and the other bits of TPN MUST be set to 0. - In case of ODUj mapped into OTUk (j=k), the TPN is not needed and this field MUST be set to 0. As per [G709-V3], The TPN is used to allow for correct demultiplexing in the data plane. When an LO ODUj is multiplexed into HO ODUk Zhang Expires April 2012 [Page 10] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 occupying one or more TSs, a new TPN value is configured at the two ends of the HO ODUk link and is put into the related MSI byte(s) in the OPUk overhead at the (traffic) ingress end of the link, so that the other end of the link can learn which TS(s) is/are used by the LO ODUj in the data plane. According to [G709-V3], the TPN field MUST be set as according to the following tables: Table 3 - TPN Assignment Rules (2.5Gbps TS granularity) +-------+-------+----+----------------------------------------------+ |HO ODUk|LO ODUj|TPN | TPN Assignment Rules | +-------+-------+----+----------------------------------------------+ | ODU2 | ODU1 |1~4 |Fixed, = TS# occupied by ODU1 | +-------+-------+----+----------------------------------------------+ | | ODU1 |1~16|Fixed, = TS# occupied by ODU1 | | ODU3 +-------+----+----------------------------------------------+ | | ODU2 |1~4 |Flexible, != other existing LO ODU2s' TPNs | +-------+-------+----+----------------------------------------------+ Table 4 - TPN Assignment Rules (1.25Gbps TS granularity) +-------+-------+----+----------------------------------------------+ |HO ODUk|LO ODUj|TPN | TPN Assignment Rules | +-------+-------+----+----------------------------------------------+ | ODU1 | ODU0 |1~2 |Fixed, = TS# occupied by ODU0 | +-------+-------+----+----------------------------------------------+ | | ODU1 |1~4 |Flexible, != other existing LO ODU1s' TPNs | | ODU2 +-------+----+----------------------------------------------+ | |ODU0 & |1~8 |Flexible, != other existing LO ODU0s and | | |ODUflex| |ODUflexes' TPNs | +-------+-------+----+----------------------------------------------+ | | ODU1 |1~16|Flexible, != other existing LO ODU1s' TPNs | | +-------+----+----------------------------------------------+ | | ODU2 |1~4 |Flexible, != other existing LO ODU2s' TPNs | | ODU3 +-------+----+----------------------------------------------+ | |ODU0 & | |Flexible, != other existing LO ODU0s and | | |ODU2e &|1~32|ODU2es and ODUflexes' TPNs | | |ODUflex| | | +-------+-------+----+----------------------------------------------+ | ODU4 |Any ODU|1~80|Flexible, != ANY other existing LO ODUs' TPNs | +-------+-------+----+----------------------------------------------+ Note that in the case of "Flexible", the value of TPN is not corresponding to the TS number as per [G709-V3]. Zhang Expires April 2012 [Page 11] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 Length (12 bits): indicates the number of bit of the Bit Map field, i.e., the total number of TS in the HO ODUk link. In case of an ODUk mapped into OTUk, there is no need to indicate which tributary slots will be used, so the length field MUST be set to 0. Bit Map (variable): indicates which tributary slots in HO ODUk that the LO ODUj will be multiplexed into. The sequence of the Bit Map is consistent with the sequence of the tributary slots in HO ODUk. Each bit in the bit map represents the corresponding tributary slot in HO ODUk with a value of 1 or 0 indicating whether the tributary slot will be used by LO ODUj or not. Padded bits are added behind the Bit Map to make the whole label a multiple of four bytes if necessary. Padded bit MUST be set to 0 and MUST be ignored. Note that the Length field in the label format can also be used to indicate the TS type of the HO ODUk (i.e., TS granularity at 1.25Gbps or 2.5Gbps) since the HO ODUk type can be known from IF_ID RSVP_HOP Object. In some cases when there is no LMP or routing to make the two end points of the link to know the TSG, the TSG information used by another end can be deduced from the label format. For example, for HO ODU2 link, the value of the length filed will be 4 or 8, which indicates the TS granularity is 2.5Gbps or 1.25Gbps, respectively. 6.2. Examples The following examples are given in order to illustrate the label format described in the previous sections of this document. (1) ODUk into OTUk mapping: In such conditions, the downstream node along an LSP returns a label indicating that the ODUk (k=1, 2, 3, 4) is directly mapped into the corresponding OTUk. The following example label indicates an ODU1 mapped into OTU1. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TPN = 0 | Reserved | Length = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (2) ODUj into ODUk multiplexing: Zhang Expires April 2012 [Page 12] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 In such conditions, this label indicates that an ODUj is multiplexed into several tributary slots of OPUk and then mapped into OTUk. Some instances are shown as follow: - ODU0 into ODU2 Multiplexing: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TPN = 2 | Reserved | Length = 8 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 1 0 0 0 0 0 0| Padded Bits (0) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This above label indicates an ODU0 multiplexed into the second tributary slot of ODU2, wherein there are 8 TS in ODU2 (i.e., the type of the tributary slot is 1.25Gbps), and the TPN value is 2. - ODU1 into ODU2 Multiplexing with 1.25Gbps TS granularity: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TPN = 1 | Reserved | Length = 8 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 1 0 1 0 0 0 0| Padded Bits (0) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This above label indicates an ODU1 multiplexed into the 2nd and the 4th tributary slot of ODU2, wherein there are 8 TS in ODU2 (i.e., the type of the tributary slot is 1.25Gbps), and the TPN value is 1. - ODU2 into ODU3 Multiplexing with 2.5Gbps TS granularity: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TPN = 1 | Reserved | Length = 16 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 1 1 0 1 0 1 0 0 0 0 0 0 0 0 0| Padded Bits (0) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This above label indicates an ODU2 multiplexed into the 2nd, 3rd, 5th and 7th tributary slot of ODU3, wherein there are 16 TS in ODU3 (i.e., the type of the tributary slot is 2.5Gbps), and the TPN value is 1. Zhang Expires April 2012 [Page 13] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 6.3. Label Distribution Procedure This document does not change the existing label distribution procedures [RFC4328] for GMPLS except that the new ODUk label MUST be processed as follows. When a node receives a generalized label request for setting up an ODUj LSP from its upstream neighbor node, the node MUST generate an ODU label according to the signal type of the requested LSP and the free resources (i.e., free tributary slots of ODUk) that will be reserved for the LSP, and send the label to its upstream neighbor node. In case of ODUj to ODUk multiplexing, the node MUST firstly determine the size of the Bit Map field according to the signal type and the tributary slot type of ODUk, and then set the bits to 1 in the Bit Map field corresponding to the reserved tributary slots. The node MUST also assign a valid TPN, which does not collide with other TPN value used by existing LO ODU connections in the selected HO ODU link, and configure the expected multiplex structure identifier (ExMSI) using this TPN. Then, the assigned TPN is filled into the label. In case of ODUk to OTUk mapping, the node only needs to fill the ODUj and the ODUk fields with corresponding values in the label. Other bits are reserved and MUST be set to 0. In order to process a received ODU label, the node MUST firstly learn which ODU signal type is multiplexed or mapped into which ODU signal type accordingly to the traffic parameters and the IF_ID RSVP_HOP Object in the received message. In case of ODUj to ODUk multiplexing, the node MUST retrieve the reserved tributary slots in the ODUk by its downstream neighbor node according to the position of the bits that are set to 1 in the Bit Map field. The node determines the TS type (according to the total TS number of the ODUk, or pre-configured TS type), so that the node, based on the TS type, can multiplex the ODUj into the ODUk. The node MUST also retrieve the TPN value assigned by its downstream neighbor node from the label, and fill the TPN into the related MSI byte(s) in the OPUk overhead in the data plane, so that the downstream neighbor node can check whether the TPN received from the data plane is consistent with the ExMSI and determine whether there is any mismatch defect. In case of ODUk to OTUk mapping, the size of Bit Map field MUST be 0 and no additional procedure is needed. Zhang Expires April 2012 [Page 14] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 Note that the procedures of other label related objects (e.g., Upstream Label, Label Set) are similar to the one described above. Note also that the TPN in the label_ERO MAY not be assigned (i.e., TPN field = 0) if the TPN is requested to be assigned locally. 6.3.1. Notification on Label Error When receiving an ODUk label from the neighbor node, the node SHOULD check the integrity of the label. An error message containing an "Unacceptable label value" indication ([RFC3209]) SHOULD be sent if one of the following cases occurs: - Invalid value in the length field. - The selected link only supports 2.5Gbps TS granularity while the Length field in the label along with ODUk signal type indicates the 1.25Gbps TS granularity; - The label includes an invalid TPN value that breaks the TPN assignment rules; - The reserved resources (i.e., the number of "1" in the Bit Map field) do not match with the Traffic Parameters. 6.4. Supporting Virtual Concatenation and Multiplication As per [RFC6344], the VCGs can be created using Co-Signaled style or Multiple LSPs style. In case of Co-Signaled style, the explicit ordered list of all labels reflects the order of VCG members, which is similar to [RFC4328]. In case of multiplexed virtually concatenated signals (NVC > 1), the first label indicates the components of the first virtually concatenated signal; the second label indicates the components of the second virtually concatenated signal; and so on. In case of multiplication of multiplexed virtually concatenated signals (MT > 1), the first label indicates the components of the first multiplexed virtually concatenated signal; the second label indicates components of the second multiplexed virtually concatenated signal; and so on. In case of Multiple LSPs style, multiple control plane LSPs are created with a single VCG and the VCAT Call can be used to associate the control plane LSPs. The procedures are similar to section 6 of [RFC6344]. Zhang Expires April 2012 [Page 15] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 6.5. Control Plane Backward Compatibility Considerations Since the [RFC4328] has been deployed in the network for the nodes that support [G709-V1], we call nodes supporting [RFC4328] "legacy nodes". Backward compatibility SHOULD be taken into consideration when the new nodes (i.e., nodes that support RSVP-TE extensions defined in this document) and the legacy nodes are interworking. For backward compatibility consideration, the new node SHOULD have the ability to generate and parse legacy labels. o A legacy node always generates and sends legacy label to its upstream node, no matter the upstream node is new or legacy, as described in [RFC4328]. o A new node SHOULD generate and send legacy labels if its upstream node is a legacy one, and generate and send new label if its upstream node is a new one. One backward compatibility example is shown in Figure 2: Path Path Path Path +-----+ ----> +-----+ ----> +------+ ----> +------+ ----> +-----+ | | | | | | | | | | | A +-------+ B +-------+ C +-------+ D +-------+ E | | new | | new | |legacy| |legacy| | new | +-----+ <---- +-----+ <---- +------+ <---- +------+ <---- +-----+ Resv Resv Resv Resv (new label) (legacy label) (legacy label) (legacy label) Figure 2 - Backwards compatibility example As described above, for backward compatibility considerations, it is necessary for a new node to know whether the neighbor node is new or legacy. One optional method is manual configuration, but it is recommended to use LMP to discover the capability of the neighbor node automatically, as described in [OTN-LMP]. When performing the HO ODU link capability negotiation: o If the neighbor node only support the 2.5Gbps TS and only support ODU1/ODU2/ODU3, the neighbor node SHOULD be treated as a legacy node. Zhang Expires April 2012 [Page 16] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 o If the neighbor node can support the 1.25Gbps TS, or can support other LO ODU types defined in [G709-V3]), the neighbor node SHOULD be treated as new node. o If the neighbor node returns a LinkSummaryNack message including an ERROR_CODE indicating nonsupport of HO ODU link capability negotiation, the neighbor node SHOULD be treated as a legacy node. 7. Supporting Multiplexing Hierarchy As described in [OTN-FWK], one ODUj connection can be nested into another ODUk (j<k) connection, which forms the multiplexing hierarchy in the ODU layer. This is useful if there are some intermediate nodes in the network which only support ODUk but not ODUj switching. For example, in Figure 3, assume that N3 is a legacy node which only supports [G709-V1] and does not support ODU0 switching. If an ODU0 connection between N1 and N5 is required, then we can create an ODU2 connection between N2 and N4 (or ODU1 / ODU3 connection, depending on policies and the capabilities of the two ends of the connection), and nest the ODU0 into the ODU2 connection. In this way, N3 only needs to perform ODU2 switching and does not need to be aware of the ODU0 connection. | | |<------------------- ODU0 Connection -------------------->| | | | | | |<---- ODU2 Connection ----->| | | | | | +----+ +----+ +----+ +----+ +----+ | N1 +---------+ N2 +=========+ N3 +=========+ N4 +---------+ N5 | +----+ +----+ +----+ +----+ +----+ ODU3 link ODU3 link ODU3 link ODU3 link Figure 3 - Example of multiplexing hierarchy The control plane signaling should support the provisioning of hierarchical multiplexing. Two methods are provided below (taking Figure 3 as example): - Using the multi-layer network signaling described in [RFC4206], [RFC6107] and [RFC6001] (including related modifications, if needed). That is, when the signaling message for ODUO connection arrives at N2, a new RSVP session between N2 and N4 is triggered to create the ODU2 connection. This ODU2 connection is treated as Zhang Expires April 2012 [Page 17] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 a Forwarding Adjacency (FA) after it is created. And then the signaling procedure for the ODU0 connection can be continued using the resource of the ODU2 FA. - The ODU2 FA-LSP is created in advance based on network planning, which is treated as an FA. Then the ODU0 connection can be created using the resource of the ODU2 FA. In this case, the ODU2 FA-LSP and inner ODU0 connections are created separately. For both methods, when creating an FA-LSP(e.g., ODU2 FA-LSP), the penultimate hop needs to choose a correct outgoing interface for the ODU2 connection, so that the destination node can support multiplexing and de-multiplexing LO ODU signal(e.g., ODU0). In order to choose a correct outgoing interface for the penultimate hop of the FA-LSP, multiplexing capability (i.e., what client signal type that can be adapted directly to this FA-LSP) should be carried in the signaling to setup this FA-LSP. In addition, when Auto_Negotiation in the data plane is not enabled, TS granularity may also be needed. 7.1. ODU FA-LSP Creation The required hierarchies and TS type for both ends of an FA-LSP is for further study. 8. Security Considerations This document introduces no new security considerations to the existing GMPLS signaling protocols. Referring to [RFC3473], further details of the specific security measures are provided. Additionally, [GMPLS-SEC] provides an overview of security vulnerabilities and protection mechanisms for the GMPLS control plane. 9. IANA Considerations - G.709 SENDER_TSPEC and FLOWSPEC objects: The traffic parameters, which are carried in the G.709 SENDER_TSPEC and FLOWSPEC objects, do not require any new object class and type based on [RFC4328]: o G.709 SENDER_TSPEC Object: Class = 12, C-Type = 5 [RFC4328] o G.709 FLOWSPEC Object: Class = 9, C-Type = 5 [RFC4328] Zhang Expires April 2012 [Page 18] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 - Generalized Label Object: The new defined ODU label (Section 6) is a kind of generalized label. Therefore, the Class-Num and C-Type of the ODU label is the same as that of generalized label described in [RFC3473], i.e., Class-Num = 16, C-Type = 2. 10. References 10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4328] D. Papadimitriou, Ed. "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for G.709 Optical Transport Networks Control", RFC 4328, Jan 2006. [RFC3209] D. Awduche et al, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC3209, December 2001. [RFC3471] Berger, L., Editor, "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003. [RFC3473] L. Berger, Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, October 2004. [RFC6344] G. Bernstein et al, "Operating Virtual Concatenation (VCAT) and the Link Capacity Adjustment Scheme (LCAS) with Generalized Multi-Protocol Label Switching (GMPLS)", RFC6344, August 2011. [RFC4206] K. Kompella, Y. Rekhter, Ed., " Label Switched Paths (LSP) Hierarchy with Generalized Multi-Protocol Label Switching (GMPLS) Traffic Engineering (TE)", RFC 4206, October 2005. [RFC6107] K. Shiomoto, A. Farrel, "Procedures for Dynamically Signaled Hierarchical Label Switched Paths", RFC6107, February 2011. Zhang Expires April 2012 [Page 19] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 [RFC6001] Dimitri Papadimitriou et al, "Generalized Multi-Protocol Label Switching (GMPLS) Protocol Extensions for Multi-Layer and Multi-Region Networks (MLN/MRN)", RFC6001, February 21, 2010. [OTN-FWK] Fatai Zhang et al, "Framework for GMPLS and PCE Control of G.709 Optical Transport Networks", draft-ietf-ccamp-gmpls- g709-framework-05.txt, September 9, 2011. [OTN-INFO] S. Belotti et al, "Information model for G.709 Optical Transport Networks (OTN)", draft-ietf-ccamp-otn-g709-info- model-01.txt, September 21, 2011. [OTN-OSPF] D. Ceccarelli et al, "Traffic Engineering Extensions to OSPF for Generalized MPLS (GMPLS) Control of Evolving G.709 OTN Networks", draft-ietf-ccamp-gmpls-ospf-g709v3-00.txt, October 13, 2011 [OTN-LMP] Fatai Zhang, Ed., "Link Management Protocol (LMP) extensions for G.709 Optical Transport Networks", draft- zhang-ccamp-gmpls-g.709-lmp-discovery-04.txt, April 6, 2011. [G709-V3] ITU-T, "Interfaces for the Optical Transport Network (OTN) ", G.709/Y.1331, December 2009. [G709-V3-A2] ITU-T, "Interfaces for the Optical Transport Network (OTN) Amendment 2", G.709/y.1331 Amendment 2, April 2011. 10.2. Informative References [G709-V1] ITU-T, "Interface for the Optical Transport Network (OTN)," G.709 Recommendation (and Amendment 1), February 2001 (November 2001). [G709-V2] ITU-T, "Interface for the Optical Transport Network (OTN)," G.709 Recommendation, March 2003. [G798-V2] ITU-T, "Characteristics of optical transport network hierarchy equipment functional blocks", G.798, December 2006. [G798-V3] ITU-T, "Characteristics of optical transport network hierarchy equipment functional blocks", G.798v3, consented June 2010. [RFC4506] M. Eisler, Ed., "XDR: External Data Representation Standard", RFC 4506, May 2006. Zhang Expires April 2012 [Page 20] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 [IEEE] "IEEE Standard for Binary Floating-Point Arithmetic", ANSI/IEEE Standard 754-1985, Institute of Electrical and Electronics Engineers, August 1985. [GMPLS-SEC] Fang, L., Ed., "Security Framework for MPLS and GMPLS Networks", Work in Progress, October 2009. 11. Contributors Jonathan Sadler, Tellabs Email: jonathan.sadler@tellabs.com Kam LAM, Alcatel-Lucent Email: kam.lam@alcatel-lucent.com Xiaobing Zi, Huawei Technologies Email: zixiaobing@huawei.com Francesco Fondelli, Ericsson Email: francesco.fondelli@ericsson.com Lyndon Ong, Ciena Email: lyong@ciena.com Biao Lu, infinera Email: blu@infinera.com 12. Authors' Addresses Fatai Zhang (editor) Huawei Technologies F3-5-B R&D Center, Huawei Base Bantian, Longgang District Shenzhen 518129 P.R.China Phone: +86-755-28972912 Email: zhangfatai@huawei.com Zhang Expires April 2012 [Page 21] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 Guoying Zhang China Academy of Telecommunication Research of MII 11 Yue Tan Nan Jie Beijing, P.R.China Phone: +86-10-68094272 Email: zhangguoying@mail.ritt.com.cn Sergio Belotti Alcatel-Lucent Optics CTO Via Trento 30 20059 Vimercate (Milano) Italy +39 039 6863033 Email: sergio.belotti@alcatel-lucent.it Daniele Ceccarelli Ericsson Via A. Negrone 1/A Genova - Sestri Ponente Italy Email: daniele.ceccarelli@ericsson.com Khuzema Pithewan Infinera Corporation 169, Java Drive Sunnyvale, CA-94089, USA Email: kpithewan@infinera.com Yi Lin Huawei Technologies F3-5-B R&D Center, Huawei Base Bantian, Longgang District Shenzhen 518129 P.R.China Phone: +86-755-28972914 Email: yi.lin@huawei.com Zhang Expires April 2012 [Page 22] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 Yunbin Xu China Academy of Telecommunication Research of MII 11 Yue Tan Nan Jie Beijing, P.R.China Phone: +86-10-68094134 Email: xuyunbin@mail.ritt.com.cn Pietro Grandi Alcatel-Lucent Optics CTO Via Trento 30 20059 Vimercate (Milano) Italy +39 039 6864930 Email: pietro_vittorio.grandi@alcatel-lucent.it Diego Caviglia Ericsson Via A. Negrone 1/A Genova - Sestri Ponente Italy Email: diego.caviglia@ericsson.com Rajan Rao Infinera Corporation 169, Java Drive Sunnyvale, CA-94089 USA Email: rrao@infinera.com John E Drake Juniper Email: jdrake@juniper.net Igor Bryskin Adva Optical EMail: IBryskin@advaoptical.com Zhang Expires April 2012 [Page 23] draft-ietf-ccamp-gmpls-signaling-g709v3-01.txt October 2011 13. Acknowledgment The authors would like to thank Lou Berger and Deborah Brungard for their useful comments to the document. Intellectual Property The IETF Trust takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in any IETF Document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. 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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. Zhang Expires April 2012 [Page 25]