Definition of ACH TLV StructureCisco Systemssboutros@cisco.comCisco Systemsstbryant@cisco.comCisco Systemsmsiva@cisco.comCisco Systemsswallow@cisco.comJuniper Networksdward@Juniper.netIP Infusion Inc.Bamankhola,Bansgali,Almora, Uttaranchal263601Indiavishwas.ietf@gmail.com
Internet
MPLSMPLSInternet-DraftIn some application of the associated channel header (ACH), it is
necessary to have the ability to include a set of TLVs to provide
additional context information for the ACH payload. This document
defines a number of TLV types.This document is a product of a joint Internet Engineering Task Force
(IETF) / International Telecommunications Union Telecommunications
Standardization Sector (ITU-T) effort to include an MPLS Transport
Profile within the IETF MPLS and PWE3 architectures to support the
capabilities and functionalities of a packet transport network as
defined by the ITU-T.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.The MPLS generic associated channel header specification (GACH) describes a TLV structure that is used
to provide additional context information for the ACH payload. This
document defines a number of TLVs that are required by the MPLS-TP
design , .This section provides the definition for a number of ACH TLV objects.
In each case the length in the TLV header is the length of only the
value component.The Null TLV provides an OPTIONAL mechanism of restoring 32bit
alignment of the following element in the packet and also provides an
OPTIONAL mechanism to reserve space in the packet to be used by TLV
objects that will be written by LSR that perform some operation on the
packet at a later time. For security reasons the value must be
zero.This TLV specifies the IPv4 source
address (SAv4) of an ACH packet.Where the packet is associated with a maintenance request/response
operation it refers to the requester of the operation, i.e. It is the
address of the Maintenance End Point that initiated the operation
being either requested, or is being responded to.This TLV specifies the IPv6 source
address (SAv6) of an ACH packet.Where the packet is associated with a maintenance request/response
operation it refers to the requester of the operation, i.e. It is the
address of the Maintenance End Point that initiated the operation
being either requested, or is being responded to.This TLV is used to carry an ITU-T Carrier Code Identifier (ICC) as
defined in M.1400 .The ICC is encoded in ASCII in a fixed format 6 byte field, with
unused trailing bytes set to NULL (0).This TLV is used to carry a Global Identifier (Global_ID) .This TLV is used to carry Network Interface ID (IF_ID) . As defined in , an IF_ID consists of a
node identifier (Node_ID) and a Logical Interface Handle (LIH), both
or which are 32 bit identifiers.The structure of the ACH authentication (auth) TLV is as
follows:The authentication proceedures and data format used is the same as
that defined in Sections 4.1, 4.2, 4.3 and 4.4 of .Each document which defines a channel type needs to define whether
an authentication TLV is required, permitted, or disallowed, and the
actions to be taken in normal and error situations.An application not supporting data origin authentication MAY use
this mechanism instead of defining its own proprietery mechanism.This specification defines a mechanism to identify a set of protocol
parameters. The necessary security considerations will be described in
the definition of the protocols that uses these parameters.IANA is requested to create a new registry in the pseudowire name
spaces: the ACH TLV Registry.The ACH TLV Registry should be initialized with the following
entries. The allocation policy for this registry is IETF consensus.ITU-T Recommendation M.1400, "Designations for
interconnections among operators' networks"