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Versions: (draft-vainshtein-pwe3-tdm-control-protocol-extensi) 00 01 02 03 04 05 06 07 RFC 5287

     Network Working Group                   A. Vainshtein (ECI Telecom)
     Internet Draft                 Y(J) Stein (RAD Data Communications)

     Intended Status:                                  Proposed Standard

     Creation Date:                                       March 20, 2008

     Expiration Date:                                     September 2008

         Control Protocol Extensions for Setup of TDM Pseudowires
                             in MPLS Networks

           draft-ietf-pwe3-tdm-control-protocol-extensi-07.txt


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 http://www.ietf.org/shadow.html.

 Abstract

 This document defines extension to the PWE3 control protocol [RFC4447]
 and PWE3 IANA allocations [RFC4446] required for setup of TDM
 pseudowires in MPLS networks.

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 Control Protocol Extensions for TDM Pseudo wires March 2008

 TABLE OF CONTENTS

 1. Introduction......................................................2
 2. PW FEC for Setup of TDM PWs.......................................3
 3. Interface Parameters for TDM PWs..................................4
   3.1. Overview......................................................4
   3.2. CEP/TDM Payload Bytes.........................................4
   3.3. CEP/TDM Bit-Rate (0x07).......................................5
   3.4. Number of TDMoIP AAL1 cells per packet........................6
   3.5. TDMoIP AAL1 mode..............................................6
   3.6. TDMoIP AAL2 Options...........................................6
   3.7. Fragmentation Indicator.......................................7
   3.8. TDM Options...................................................7
 4. Extending CESoPSN Basic NxDS0 Services with CE Application
 Signaling............................................................9
 5. LDP Status Codes.................................................10
 6. Using the PW Status TLV..........................................10
 7. IANA Considerations..............................................11
 8. Security Considerations..........................................11
 9. Acknowledgements.................................................11
 10. Disclaimer of Validity..........................................12
 11. Normative References............................................12
 12. Informational References........................................12
 13. Full Copyright Statement........................................13
 14. Acknowledgement.................................................13
 15. Authors' Addresses..............................................13


 1. Introduction

 This document defines extension to the PWE3 control protocol [RFC4447]
 and PWE3 IANA allocations [RFC4446] required for setup of TDM
 pseudowires in MPLS networks.

 Structure-agnostic TDM pseudowires have been specified in [RFC4553]
 and structure-aware ones in [RFC5086] and [RFC5087].

 [RFC4447] defines extensions to LDP [RFC5036] that are required to
 exchange PW labels for PWs emulating various Layer 2 services
 (Ethernet, FR, ATM, HDLC etc.). Setup of TDM PWs requires both
 interpretation of the existing information elements of these extensions
 and exchange of additional information.

 Setup of TDM PWs using L2TPv3 will be defined in a separate document.

 Status of attachment circuits of TDM PWs can be exchanged between the
 terminating PEs using the PW Status mechanism defined in [RFC4447]
 without any changes. However, usage of this mechanism is NOT
 RECOMMENDED for TDM PWs, since indication of status of the TDM
 attachment circuits is carried in-band in the data plane.


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 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 RFC 2119.

 2. PW FEC for Setup of TDM PWs

 [RFC4447] uses LDP Label Mapping message [RFC5036] for advertising
 the FEC-to-PW Label binding, and defines two types of PW FEC that can
 be used for this purpose:


 1. PWId FEC (FEC 128). This FEC contains:
     a) PW type
     b) Control bit (indicates presence of the control word)
     c) Group ID
     d) PW ID
     e) Interface parameters
 2. Generalized PW FEC (FEC 129). This FEC contains only:
     a) PW type
     b) Control bit
     c) AGI, SAII and TAII that replace the PW ID

 The Group ID and the Interface parameters are contained in separate
 TLVs, called the PW Grouping TLV and the Interface Parameters TLV.

 Either of these types of PW FEC MAY be used for setup of TDM PWs with
 appropriate selection of PW types and interface parameters.


 The PW Types for TDM PWs are allocated in [RFC4446] as follows:

 o  0x0011  Structure-agnostic E1 over Packet [RFC4553]
 o  0x0012  Structure-agnostic T1 (DS1) over Packet [RFC4553]
 o  0x0013  Structure-agnostic E3 over Packet [RFC4553]
 o  0x0014  Structure-agnostic T3 (DS3) over Packet [RFC4553]
 o  0x0015  CESoPSN basic mode [RFC5086]
 o  0x0016  TDMoIP AAL1 mode [RFC5087]
 o  0x0017  CESoPSN TDM with CAS [RFC5086]
 o  0x0018  TDMoIP AAL2 mode [RFC5087]

 The two endpoints MUST agree on the PW type, as both directions of the
 PW are required to be of the same type.

 The Control bit MUST always be set for TDM PWs since all TDM PW
 encapsulations always use a control word.

 PW Type 0x0012 MUST also be used for setup of structure-agnostic TDM
 PWs between a pair of J1 attachment circuits (see [RFC4805]).


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 3. Interface Parameters for TDM PWs
   3.1.     Overview

 The interface parameters that are relevant for setup of the TDM PWs are
 listed below.

 -------------------------------------------------------------
 |   Interface Parameter |  Type      | Length | Description |
 |-----------------------|------------|--------|-------------|
 | CEP/TDM Payload Bytes | 0x04       | 4      |Section 3.2  |
 |-----------------------|------------|--------|-------------|
 | CEP/TDM Bit-Rate      | 0x07       | 6      |Section 3.3  |
 |-----------------------|------------|--------|-------------|
 | Number of TDMoIP AAL1 |TBA by IANA.| 4      |Section 3.4  |
 | Cells per Packet      |Suggested:  |        |             |
 |                       | 0x0E       |        |             |
 |-----------------------|-------=----|--------|-------------|
 | TDMoIP AAL1 mode      |TBA by IANA.| 4      |Section 3.5  |
 |                       |Suggested:  |        |             |
 |                       | 0x10       |        |             |
 |-----------------------|------------|--------|-------------|
 | TDMoIP AAL2 Options   |TBA by IANA | 8 or   |Section 3.6  |
 |                       |Suggested:  | larger |             |
 |                       | 0x11       |see note|             |
 |-----------------------|------------|--------|-------------|
 | Fragmentation         | 0x09       |  4     |Section 3.7  |
 | Indicator             |            |        |             |
 |-----------------------|------------|--------|-------------|
 | TDM Options           | 0x0B       |  4, 8, |Section 3.8  |
 |                       |            | or 12  |             |
 -------------------------------------------------------------

 If not explicitly indicated otherwise in the appropriate description,
 the value of the interface parameter is interpreted as an unsigned
 integer of the appropriate size (16 or 32 bits).

 Note: The length of basic TDMoIP AAL2 Options interface parameter is 8
 bytes, and when the optional CID mapping bases field is used there is
 one additional byte for each trunk transported. Thus if 1 trunk is
 being supported, this message occupies 9 bytes. Since there can be no
 more than 248 CIDs in a given PW, this can never exceed 256 (this when
 when each channel comes from a different trunk). 248 channels
 translates to less than 9 E1s, and so for this case the length is no
 more than 17 bytes. A single PE is not required to support more than 10
 AAL2 PWs (i.e., up to 2480 individual channels, which is more than
 carried by a fully populated STM1). Thus the memory required to store
 all the AAL2 mapping information is typically between 80 and 170 bytes
 per PE.


   3.2.     CEP/TDM Payload Bytes

 This parameter is used for setup of all SAToP and CESoPSN PWs (i.e. PW

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 types 0x0011, 0x0012, 0x0013, 0x0014, 0x0015 and 0x0017) and employs
 the following semantics:

 1. The two endpoints of a TDM PW MUST agree on the same value of
     this parameter for the PW to be set up successfully.
 2. Presence of this parameter in the PWId FEC or in the Interface
     Parameters Field TLV is OPTIONAL. If this parameter is omitted,
     default payload size defined for the corresponding service (see
     [RFC4553], [RFC5086]) MUST be assumed
 3. For structure-agnostic emulation, any value consistent with the
     MTU of the underlying PSN MAY be specified

 4. For CESoPSN PWs:
     a) The specified value P MUST be an integer multiple of N,
        where N is the number of timeslots in the attachment
        circuit
     b) For trunk-specific NxDS0 with CAS:
        i)   (P/N) MUST be an integer factor of the number of
           frames per corresponding trunk multiframe (i.e. 16
           for an E1 trunk and 24 for a T1 or J1 trunk)
        ii)  The size of the signaling sub-structure is not
           accounted for in the specified value P.
 5. This parameter MUST NOT be used for setup of TDMoIP PWs (i.e.,
     PWs with PW types 0x0016 and 0x0018).

   3.3.     CEP/TDM Bit-Rate (0x07)

 This interface parameter represents the bit-rate of the TDM service in
 multiples of the "basic" 64 Kbit/s rate. Its usage for all types of TDM
 PWs assumes the following semantics:

 1. This interface parameter MAY be omitted if the attachment circuit
     bit-rate can be unambiguously derived from the PW Type (i.e. for
     structure-agnostic emulation of E1, E3 and T3 circuits). If this
     value is omitted for the structure-agnostic emulation of T1 PW
     Type, the basic emulation mode MUST be assumed.
 2. If present, only the following values MUST be specified for
     structure-agnostic emulation (see [RFC4553]:
     a) Structure-agnostic E1 emulation  - 32
     b) Structure-agnostic T1 emulation:
        i)   MUST be set to 24 in the basic emulation mode
        ii)  MUST be set to 25 for the "Octet-aligned T1" emulation mode
     c) Structure-agnostic E3 emulation  - 535
     d) Structure-agnostic T3 emulation  - 699
 3. For all kinds of structure-aware emulation, this parameter MUST be
     set to N where N is the number of DS0 channels in the corresponding
     attachment circuit.

 Note: The value 24 does not represent the actual bit-rate of the T1 or
 J1 circuit (1,544 Mbit/s) in units of 64 kbit/s. The values mentioned
 above are used for convenience.


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 Note: A 4-byte space is reserved for this parameter for compatibility
 with [RFC4842].

   3.4.     Number of TDMoIP AAL1 cells per packet

 This parameter MAY be present for TDMoIP AAL1 mode PWs (PW type 0x0016)
 and specifies the number of 48-byte AAL1 PDUs per MPLS packet. Any
 values consistent with the MTU of the underlying PSN MAY be specified.
 If this parameter is not specified it defaults to 1 PDU per packet for
 low bit-rates (CEP/TDM Bit-Rate less than or equal to 32), and to 5 for
 high bit-rates (CEP/TDM Bit-Rate of 535 or 699).

   3.5.     TDMoIP AAL1 mode

 This parameter MAY be present for TDMoIP AAL1 mode PWs (PW type 0x0016)
 and specifies the AAL1 mode. If this parameter is not present, the AAL1
 mode defaults to "structured". When specified, the values have the
 following significance:
    0 - unstructured AAL1
    2 - structured AAL1
    3 - structured AAL1 with CAS.
 The two endpoints MUST agree on the TDMoIP AAL1 mode.

   3.6.     TDMoIP AAL2 Options

 This parameter MUST be present for TDMoIP AAL2 mode PWs (PW type
 0x0018) and has the following format:

     0                   1                   2                   3
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |    0x0F       |    Length     | V |      ENCODING             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                      Maximum Duration                         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                      CID mapping bases                        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

 The fields in this parameter are defined as follows:

 V defines the VAD capabilities. Its values have the following
 significance:
      0 means that activity is only indicated by signaling
      1 means that voice activity detection is employed
      3 means this channel is always active. In particular, this channel
      may be used for timing recovery.

 Encoding specifies native signal processing performed on the payload.
 When no native signal processing is performed (i.e. G.711 encoding)
 this field MUST be zero. Other specific values that can be used in this
 field are beyond the scope of this specification, but the two
 directions MUST match for the PW setup to succeed.


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 Maximum Duration specifies the maximum time allowed for filling an AAL2
 PDU, in units of 125 microseconds. For unencoded 64 kbps channels this
 numerically equals the maximum number of bytes per PDU, and MUST be
 less than 64. For other encoding parameters, larger values may be
 attained.

 CID mapping bases is an OPTIONAL parameter, its existence and length
 determined by the length field. If the mapping of AAL2 CID values to
 physical interface and time slot is statically configured, or if AAL2
 switching [Q.2630.1] is employed, this parameter MUST NOT appear. When
 it is present, and the channels belong to N physical interfaces (i.e. N
 E1s or T1s), it MUST be N bytes in length. Each byte represents a
 number to be subtracted from the CID to get the timeslot number for
 each physical interface. For example, if the CID mapping bases
 parameter consists of the bytes 20 and 60, this signifies that timeslot
 1 of trunk 1 corresponds to CID 21 and timeslot 1 of trunk 2 is called
 61.


   3.7.     Fragmentation Indicator

 This interface parameter is specified in [RFC4446] and its usage is
 explained in [RFC4623]. It MUST be omitted in the FEC of all TDM PWs
 excluding trunk-specific NxDS0 services with CAS using the CESoPSN
 encapsulation. In case of these services, it MUST be present in the PW
 FEC if the payload size specified value P differs from Nx(number of
 frames per trunk multiframe).


   3.8.     TDM Options

 This is a new interface parameter. Its Interface Parameter ID (0x08)
 has been assigned by IANA, and its format is shown in Fig. 1 below:

     0                   1                   2                   3
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Parameter ID |    Length     |R|D|F|X|SP |CAS|   RSVD-1      |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |0|     PT      |   RSVD-2      |               FREQ            |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                         SSRC                                  |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

          Figure 1. Format of the TDM Options Interface Parameter


 The fields shown in this diagram are used as follows:


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 Parameter ID       Identifies the TDM PW Options interface parameter,
                     value TBA by IANA
 Length             4, 8 or 12 (see below)
 R                  The RTP Header Usage bit: if set, indicates that
                     the PW endpoint distributing this FEC expects to
                     receive RTP header in the encapsulation. RTP header
                     will be used only if both endpoints expect to
                     receive it. If this bit is cleared, Length MUST be
                     set to 4, otherwise it MUST be either 8 or 12 (see
                     below). If the peer PW end point cannot meet this
                     requirement, the Label Mapping message containing
                     the FEC in question MUST be rejected with the
                     appropriate status code (see Section 4 below).
 D                  The Differential timestamping Mode bit: if set,
                     indicates that the PW endpoint distributing this
                     FEC expects the peer to use Differential
                     timestamping mode in the packets sent to it. If the
                     peer PW end point cannot meet this requirement, the
                     Label Mapping message containing the FEC in
                     question MUST be rejected with the appropriate
                     status code (see Section 4 below).
 F, X               Reserved for future extensions. MUST be cleared
                     when distributed and MUST be ignored upon reception
 SP                 Encodes support for the CESoPSN signaling packets
                     (see [RFC5086]):
                     o  '00' for PWs that do not use signaling
                        packets
                     o  '01' for CESoPSN PWs carrying TDM data
                        packets and expecting CE application
                        signaling packets in a separate PW
                     o  '10' for a PW carrying CE application
                        signaling packets with the data packets in a
                        separate PW
                     o  '11' - for CESoPSN PWs carrying TDM data and
                        CE application signaling on the same PW
 CAS                MUST be cleared for all types of TDM PWs excluding
                     trunk-specific NxDS0 services with CAS. For these
                     services it encodes the trunk framing like
                     following:
                     o  '01' - an E1 trunk
                     o  '10' - a T1/ESF trunk
                     o  '11' - a T1 SF trunk
 RSVD-1 and RSVD-2  Reserved bits, MUST be set to 0 by the PW endpoint
                     distributing this FEC and MUST be ignored by the
                     receiver
 PT                 Indicates the value of Payload Type in the RTP
                     header expected by the PW endpoint distributing
                     this FEC. Value 0 means that PT value check will
                     not be used for detecting malformed packets
 FREQ               Frequency of timestamping clock in units of 8 kHz
 SSRC               Indicates the value of SSRC ID in the RTP header
                     expected by the PW endpoint distributing this FEC.
                     Value 0 means that SSRC ID value check will not be

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                     used for detecting misconnections. Alternatively,
                     Length can be set to 8 in this case.


 Notes:

 1. This interface parameter MAY be omitted in the following cases:
     a) SAToP PWs that do not use RTP header [RFC4553]
     b) Basic CESoPSN NxDS0 services without CE application
        signaling [RFC5086]
     c) TDMoIP AAL1 mode 0 or 2 PWs that do not use RTP
     d) TDMoIP AAL2 PWs that do not relay CAS signaling and do
        not use RTP.
 2. This interface parameter MUST be present in the following cases:
     a) All TDM PWs that use RTP header
     b) CESoPSN PWs that carry basic NxDS0 services and use
        CESoPSN signaling packets to carry CE application
        signaling. This case is discussed in detail in Section 4
        below
     c) CESoPSN PWs that carry trunk-specific NxDS0 services with
        CAS
     d) TDMoIP AAL1 mode 1 PWs
     e) TDMoIP AAL2 PWs that relay CAS signaling.
 3. If RTP header and possibly the Differential timestamping mode
     are used, the value of the Length field MUST be set to 8 or 12
     in order to accommodate the Timestamping Clock Frequency and
     SSRC fields
 4. Usage or non-usage of the RTP header MUST match for the two
     directions making up the TDM PW. However, it is possible to use
     Differential timestamping mode in just one direction.


 4. Extending CESoPSN Basic NxDS0 Services with CE Application Signaling

 [RFC5086] defines that basic NxDS0 services can be extended to carry CE
 application signaling (e.g., CAS) in special signaling packets carried
 in a separate PW.

 The following rules define setup of matching pairs of CESoPSN PWs using
 the PW Id FEC and the extensions defined above:

 1. The two PWs MUST:
     a) Have the same PW Type
     b) Use the same setup method (i.e. either both use the PWId
        FEC, or both use the Generalized PW FEC)
     c) Have the same values of all the Interface Parameters
        listed in Section 3.1 above with the exception of the
        code point in the SP field of the TDM Options parameter:
        i)   For the PW carrying TDM data packets the SP bits
           MUST be set to '01'
        ii)  For the PW carrying the signaling packets, the SP
           bits MUST set to '10'
 2. If the PWId FEC has been used:

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     a) The value of PW ID for the CESoPSN PW carrying TDM data
        packets MUST be even
     b) The value of PW ID for the CESoPSN PW carrying CE
        application signaling MUST be the next (odd) value after
        the (even) PW ID of the CESoPSN PW carrying TDM data
        packets

 When using the Generalized PW FEC for setup of the two PWs, no specific
 rules for matching the two FECs are defined. Implementation specific
 mechanisms MAY be employed to verify the proper matching of the TDM
 data PW with its associated CE signaling PW.

 If one of the two associated PWs has been established and the other
 failed to be established, or for any reason fails after having been
 established, the established PW MUST be torn down.

 5. LDP Status Codes

 In addition to the status codes defined in sections 5.1 and 7.2 of
 [RFC4447], the following status codes defined in [RFC4446] MUST be used
 to indicate the reason of failure to establish a TDM PW:

 1. Incompatible bit rate:
     a) In the case of mismatch of T1 encapsulation modes (basic
        vs. octet-aligned)
     b) In case of mismatch in the number of timeslots for NxDS0
        basic services or trunk-specific NxDS0 services with CAS
 2. CEP/TDM misconfiguration:
     a) In the case of mismatch in the desired usage of RTP
        header
     b) In the case of mismatch of the desired timestamping clock
        frequency
     c) In the case of mismatch of expected signaling packets
        behavior for basic CESoPSN NxDS0 services extended to
        carry CE application signaling in separate signaling
        packets
     d) In the case of trunk-specific NxDS0 services with CAS if
        the framing types of the trunks are different
     e) In the case of TDMoIP AAL1 PWs with different AAL1 modes
        specified by the end points
 3. The generic misconfiguration error MAY be used to indicate any
     setup failure not covered above.

 In cases 2a, 2b, 2c and 2e above, the user MAY reconfigure the end
 points and attempt to setup the PW once again.

 In the case 2d the failure is fatal.

 Note that setting of the Control bit (see section 2 above) to zero MUST
 result in an LDP status of "Illegal C-Bit".

 6. Using the PW Status TLV


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 The TDM PW control word carries status indications for both attachment
 circuits (L and M fields) and the PSN (R field) indication (see
 [RFC4553], [RFC5086] and [RFC5087]). Similar functionality is available
 via use of the PW Status TLV (see [RFC4447], Section 5.4.2).
 If the latter mechanism is employed, the signaling PE sends its peer a
 PW Status TLV for this PW, setting the appropriate bits (see [RFC4446],
 Section 3.5):

 o  Pseudo Wire Not Forwarding
 o  Local Attachment Circuit (ingress) Receive Fault
 o  Local Attachment Circuit (egress) Transmit Fault
 o  Local PSN-facing PW (ingress) Receive Fault
 o  Local PSN-facing PW (egress) Transmit Fault.

 As long as the TDM PW interworking function is operational, usage of
 the Status TLV is NOT RECOMMENDED in order to avoid contention between
 status indications reported by the data and control plane. However, if
 the TDM PW interworking function (IWF) itself fails while the PWE3
 control plane remains operational, a Status TLV with all of the above
 bits set SHOULD be sent.

 7. IANA Considerations

 Most of the IANA assignments required by this draft are already listed
 in [RFC4446]. Additional assignments are required for three Interface
 Parameters Sub-TLV type values (see Section 3.1):

 o  Number of TDMoIP AAL1 cells per packet (suggested value - 0x0E)
 o  TDMoIP AAL1 mode (suggested value - 0x10)
 o  TDMoIP AAL2 Options (suggested value - 0x11).

 8. Security Considerations

 This draft does not have any additional impact on security of PWs above
 that of basic LDP-based setup of PWs specified in [RFC4447].

 9. Acknowledgements

 Sharon Galtzur has reviewed one of the previous versions of this
 document.
 Y(J)S would like to thank Barak Schlosser for helpful discussions.

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 Disclaimer of Validity

 The IETF 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 this 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.  Information on the procedures with respect to rights
 in RFC documents can be found in BCP 78 and BCP 79.

 Copies of IPR disclosures made to the IETF Secretariat and any
 assurances of licenses to be made available, or the result of an
 attempt made to obtain a general license or permission for the use
 of such proprietary rights by implementers or users of this
 specification can be obtained from the IETF on-line IPR repository
 at http://www.ietf.org/ipr.

 The IETF invites any interested party to bring to its attention
 any copyrights, patents or patent applications, or other
 proprietary rights that may cover technology that may be required
 to implement this standard.  Please address the information to the
 IETF at ietf-ipr@ietf.org.

 10.  Normative References

 [RFC5036] L. Andersson et al, LDP Specification, RFC 5036, IETF, 2007

 [RFC4447] L. Martini et al, Pseudowire Setup and Maintenance using LDP,
 RFC 4447, 2006

 [RFC4446] L. Martini, IANA Allocations for Pseudo Wire Edge to Edge
 Emulation (PWE3), RFC 4446, 2006

 [RFC4623] A. Malis, M. Townsley, PWE3 Fragmentation and Reassembly, RFC
 4623, 2006

 [RFC4553] A. Vainshtein, Y. Stein, Structure-Agnostic TDM over Packet
 (SAToP), RFC 4553, 2006

 11.  Informational References

 [RFC5086] A. Vainshtein et al, Structure-aware TDM Circuit Emulation
 Service over Packet Switched Network (CESoPSN), RFC 5086, 2007

 [RFC5087] Y(J) Stein et al, TDM over IP, RFC 5087 2007.

 [Q.2630.1] ITU-T Recommendation Q.2630.1, December 1999, AAL type 2
 signaling protocol - Capability set 1


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 [RFC4805] O. Nicklass, Definitions of Managed Objects for the DS1, J1,
 E1, DS2, and E2 Interface Types, RFC 4805, 2007

 [RFC4842] A. Malis et al, Synchronous Optical Network/Synchronous
 Digital Hierarchy (SONET/SDH) Circuit Emulation over Packet (CEP), RFC
 4842, 2007

 12.  Full Copyright Statement

 Copyright (C) The IETF Trust (2008).

 This document is subject to the rights, licenses and restrictions
 contained in BCP 78, and except as set forth therein, the authors
 retain all their rights.

 This document and the information contained herein are provided on an
 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
 THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.


 13.  Acknowledgement

 Funding for the RFC Editor function is currently provided by the
 Internet Society.

 14.  Authors' Addresses

 Alexander ("Sasha") Vainshtein
 ECI Telecom
 30 ha-Sivim St.,
 PO Box 500 Petah-Tiqva, 49517 Israel
 email: Alexander.Vainshtein@ecitele.com

 Yaakov (Jonathan) Stein
 RAD Data Communications
 24 Raoul Wallenberg St., Bldg C
 Tel Aviv  69719
 ISRAEL

 Phone: +972 3 645-5389
 Email: yaakov_s@rad.com



 Vainshtein and Stein       Expires September 2008           [Page 13]


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