TDP (the Tag Distribution
Protocol) is a two party protocol that runs over a connection
oriented transport layer with guaranteed sequential delivery. Tag
switching routers use this protocol to communicate tag binding
information to their peers. TDP supports multiple network layer
protocols including, but not limited to IPv4, IPv6, IPX and
AppleTalk. Tag Switching Routers (TSRs) create tag bindings, and
then distribute the tag binding information among other TSRs. TDP
provides the means for TSRs to distribute, request, and release tag
binding information for multiple network layer protocols. TDP also
provides the means to open, monitor and close TDP sessions and to
indicate errors that occur during those sessions. TCP is used as the
transport for TDP. (Compliant with IETF
draft-doolan-tdp-spec-01.)
The format of the packet is
shown in the following illustration:
Version
Length
TDP
identifier
Reserved
TDP packet
structure
Version The version number
of the protocol.
Length The length in
octets of the data portions.
TDP
identifier A unique identifier for the TSR that generated the
PDU.
Reserved A reserved
field.
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protocol?
Multi-Protocol
Label Switching (MPLS) is a set of procedures for augmenting network
layer packets with "label stacks", thereby turning them into labeled
packets. It defines the encoding used by a label switching router to
transmit such packets over PPP and LAN links. It is an Ethernet Tag
Switching protocol. This protocol attaches labels to IP and IPv6
protocols in the network layer, after the data link layer headers,
but before the network layer headers. It inserts a 4 or 8 byte
label. (Compliant with the IETF draft-rosen-tag-stack-02.txt on
the subject of Label switching.)
The format of the MPLS
label stack is shown in the following illustration:
1
2
3
4
5
6
7
8 bit
Label (20 bits)
CoS
S
TTL
MPLS label
stack
Label The field contains
the actual value for the label. This gives information on the
protocol in the network layer and further information needed to
forward the packet.
Class of
Service (CoS) The setting of this field affects the scheduling and or
discard algorithms which are applied to the packet as it is
transmitted through the network.
S Bottom of the
Stack. This bit is set to one for the last entry in the label stack
and zero for all other label stack entries.
Time to
Live (TTL) This 8 bit field is used to encode a time to live
value.
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about testing this protocol?
