CN105634647A - Method and system for realizing forward compatibility of MSTP (Multi-Service Transfer Platform) equipment to PTN (Packet Transport Network) equipment platform - Google Patents

Abstract

The invention discloses a method and a system for realizing forward compatibility of MSTP (Multi-Service Transfer Platform) equipment to a PTN (Packet Transport Network) equipment platform. The method comprises: decomposing PDH (Plesiochronous Digital Hierarchy) signals or SDH (Synchronous Digital Hierarchy) signals into continuous PDH payload E1/T1/E3/T3 signals or SDH payload VC12/VC-4 signals; cutting the continuous PDH payload signals or the SDH payload signals into PDH or SDH payload data slices with fixed lengths according to an SAToP (Structure-Agnostic TDM over Packet) protocol or a CEP (Circuit Emulation over Packet) protocol based on the lengths required by a system, forming an SAToP frame format or a CEP frame format by using the data slices as payloads, packaging the data slices into an Ethernet frame by adding an MPLS (Multi Protocol Label Switching) or VLAN (Virtual Local Area Network) identifier, and sending the Ethernet frame to an opposite end; sending, by the opposite end, the received Ethernet frame to a corresponding SAToP receiving module or a CEP receiving module, separately recovering the continuous PDH payload signals or the SDH payload signals by using a differential clock mode, and obtaining PDH signals or SDH signals via a signal recombination module. By adopting the method and the system, the reformed PTN equipment has the function of the MSTP equipment, so that the networking capability and range of the PTN equipment are improved, and the life cycle of the equipment is prolonged.

Description

Realize the method and system of PTN device platform forward compatibility MSTP equipment

Technical field

The present invention relates to the communications field, be specifically related to realize the method and system of PTN device platform forward compatibility MSTP equipment.

Background technology

At present, data delivery platform is PTN (PacketTransportNetwork mostly, grouping conveying network) the defined PTN device of standard, this equipment is suitable for Packet Service (such as Ethernet, IP operation) transmission and exchange, but do not possess SDH (SynchronousDigitalHierarchy, Synchronous Digital Hierarchy) time gas exchange of equipment and transfer capability, this causes that PTN device can not forward compatibility SDH network, this defect causes that PTN device can not effectively utilize the existing MSTP (multi-service transport platform based on SDH, Multi-ServiceTransferPlatform) investment of equipment, shorten the life cycle of this kind equipment, cause the wasting of resources, from market cost angle analysis, it is desirable to be able to the PTN device platform of forward compatibility MSTP equipment.

Summary of the invention

The technical problem to be solved be PTN device platform can not before the problem of compatible MSTP equipment mutually.

In order to solve above-mentioned technical problem, the technical solution adopted in the present invention is to provide a kind of system realizing PTN device platform forward compatibility MSTP equipment,

Include at PTN device platform end:

Signal decomposition module, the every road PDH signal or the SDH signals that receive PTN device platform decompose, it is thus achieved that PDH signal payload E1/T1/E3/T3 or SDH signal payload VC12/VC4, and send;

SAToP sending module, PDH signal payload E1/T1/E3/T3 described in continuous print is cut into the PDH payload data section of regular length by the length according to system requirements, the PDH payload data section of Bing Weimei road, plus FixedRTP frame head and SAToP control word, obtains the SAToP frame being payload with the section of described PDH payload data;

CEP sending module, SDH signal payload VC12/VC4 described in continuous print is cut into the SDH payload data section of regular length by the length according to system requirements, the SDH payload data section of Bing Weimei road, plus FixedRTP frame head and CEP agreement frame head, obtains the CEP frame being payload with the section of described SDH payload data;

Ethernet frame package module, adds MPLS/VLAN mark, the corresponding payload E1/T1/E3/T3/VC4/VC12 passage of each MPLS/VLAN mark for described SAToP frame or CEP frame, is packaged into SAToP or CEP ethernet frame;

Ethernet frame sending module, by being sent to opposite end based on the exchange network of ethernet frame by packaged ethernet frame;

Include in opposite end:

Ethernet frame receiver module, forwards respectively accordingly by described SAToP or the CEP ethernet frame received;

SAToP receiver module, restores the section of PDH payload data from described SAToP ethernet frame, and described PDH payload data slice graph display is generated continuous print PDH signal payload E1/T1/E3/T3;

CEP receiver module, restores the section of SDH payload data from described CEP ethernet frame, and described SDH payload data slice graph display is generated continuous print SDH signal payload VC12/VC-4;

Signal recombination module, is reduced into PDH signal or SDH signal by the continuous print PDH signal payload E1/T1/E3/T3 of restructuring or SDH signal payload VC12/VC-4.

In such scheme, described SAToP ethernet frame format is made up of label switched path or pseudo-wire label stacking, SAToP control word, FixedRTP frame head and E1/T/1/E3/T3 data slicer.

In such scheme, described CEP ethernet frame format is made up of label switched path or pseudo-wire label stacking, CEP agreement frame head, FixedRTP frame head and VC12/VC4 data slicer.

In such scheme, the form of described FixedRTP frame head includes:

Version number V, it is necessary to arrange 2;

Filling bit P, sender must be set to 0, and recipient must ignore this bit;

Definition extended bit X, sender must be set to 0, and recipient must ignore this bit;

Effect source count bits CC, sender must be set to 0, and recipient must ignore this bit;

Identification bit M, it is necessary to be set to 0 by sender, and recipient must ignore this bit;

Payload type PT [0:6], the value of PT by the PW dynamic value range assignment in each direction, should can use same PT value between different CEPPW and direction;

Bag sequence number SequenceNumber [0:15], often sends a circulation wrapped from 0 to 0xFFFF and is incremented by, and opposite end can detect whether packet loss and according to this to the bag rearrangement received, and this value is identical with the sequence number value in control word;

Timestamp value Timestamp [0:31], is used for carrying timing information;

Synchronisation source SSRC [0:31], can be used for detecting incorrect link.

In such scheme, described SAToP control word is made up of following field:

Lbit, for alarm indication bit, Lbit set represents that the TDM payload in bag is invalid, when opposite end receives the bag that Lbit is 1, can send complete " 1 " to corresponding TDM port;

Rbit, for remote bug indication bit, Rbit puts 1 expression far-end receiving and loses;

RSVandFRG, for reserved and segmentation bits, sender must be set to 0, and recipient must ignore this bit;

Length [0:5], for length field, if not 0, it indicates that the length of SAToP frame head; If employing RTP frame head, add the length of this RTP frame head length and load, and if this length total value less than or equal to 64 byte time, length field must be set to actual value, is otherwise set to 0;

SequenceNumber [0:15], for bag sequence number, often one data slicer of transmission is incremented by from 0 to 0xFFFF circulation, and opposite end can detect whether packet loss and according to this to the bag rearrangement received.

In such scheme, CEPHeader is made up of following field:

Lbit, for alarm indication bit, Lbit set represents that the TDM payload in data slicer is invalid, when opposite end receives the data slicer that Lbit is 1, can send complete " 1 " to corresponding TDM port;

Rbit, for remote bug indication bit, Rbit set represents that far-end receiving is lost;

NandPbits, for pointer negative justification and positive justification indication bit, this bit is used for clearly relaying the Pointer Justification Event of the negative, positive through PSN, and it is optional for using N and P bit, and without use, N and P bit must be set to 0;

FRG, for segmentation bits, sender must be set to 0, and recipient must ignore this bit;

Length [0:5], for length field, if not 0, it indicates that the length of CEP frame head; If employing RTP frame head, add the length of this RTP frame head length and load, and if the total value of this length less than or equal to 64 byte time, length field must be set to actual value, is otherwise necessary for being set to 0;

SequenceNumber [0:15], for bag sequence number, often one data slicer of transmission is incremented by from 0 to 0xFFFF circulation, and opposite end can detect whether packet loss and according to this to the bag rearrangement received;

StructurePointer [0:11], for structured fingers value, structured fingers must comprise the biasing of the first character joint of the SONET structure in payload package, SPE is emulated, structured fingers is positioned at the j1 byte of CEP data slicer, emulating for VT, structured fingers is positioned at the V5 byte of data slicer; Structured fingers value scope from " 0 " to " 0xFFE ", described " 0 " represents first character and saves followed by CEP frame head, and when data slicer does not carry J1 or V5 byte time, structured fingers must be set to 0xFFF;

Reserved, for reserved field, sender must be set to 0, and recipient must ignore this bit.

In such scheme, NandPbits arrange description as follows:

When N, P are set to 0, pointer-free adjustment is described;

When N, P are set to 1, Loss Of Pointer alarm is described;

When N be set to 0, P be set to 1 time, positive pointer regulation is described;

When N be set to 1, P be set to 0 time, negative pointer regulation is described.

In such scheme, the form of described SAToP or CEP ethernet frame includes:

Source address;

Destination address;

TPID tag protocol identifier+VLAN;

Ethernet frame type;

SAToP frame format or CEP frame format;

Frame Check Sequence.

In such scheme,

TPID tag protocol identifier value is expressed as 0x8100 with 16 systems;

The channel number one_to_one corresponding of VLAN value and label switched path definition;

Ethernet frame type value is expressed as 0x8847 with 16 systems;

Label switched path value represents with 16 systems, and each label switched path value and E1/T1/E3/T3/VC12/VC4 signalling channel one_to_one corresponding.

Present invention also offers a kind of method realizing PTN device platform forward compatibility MSTP equipment, comprise the following steps:

Step A100, the every road PDH signal received by PTN device platform or SDH signal decomposition are continuous print PDH signal payload E1/T1/E3/T3 or SDH signal payload VC12/VC-4;

Step A200, according to the length of system requirements by continuous print PDH signal payload E1/T1/E3/T3 or SDH signal payload VC12/VC-4, it is cut into PDH payload or the section of SDH payload data of regular length according to SAToP agreement or CEP agreement, and forms SAToP frame or CEP frame for payload to cut into slices containing PDH payload or SDH payload data respectively;

Step A300, add MPLS/VLAN mark for SAToP frame or CEP frame, the corresponding payload E1/T1/E3/T3/VC4/VC12 passage of each MPLS/VLAN mark, it is packaged into SAToP or CEP ethernet frame;

Step A400, by based on the exchange network of ethernet frame, packaged SAToP or CEP ethernet frame being delivered to opposite end;

SAToP or the CEP ethernet frame of reception is distributed to corresponding SAToP receiver module or CEP receiver module by step A500, opposite end, recover continuous P DH signal payload or SDH signal payload respectively, and obtain PDH signal or SDH signal through signal restructuring, wherein, different PDH signals or SDH signalling channel are identified by MPLS/VLAN to be distinguished.

The present invention is by the transformation to PTN device, make it have the function of MSTP equipment, it both can as PTN device and PTN device networking, also can as MSTP equipment forward compatibility MSTP equipment network, it is alternatively arranged as the switching node equipment of PTN network and MSTP network, thus expanding networking capability and the scope of PTN device, extend the life cycle of this kind equipment.

Accompanying drawing explanation

Fig. 1 is the system architecture diagram realizing PTN device platform forward compatibility MSTP equipment provided by the invention;

Fig. 2 is the method flow diagram realizing PTN device platform forward compatibility MSTP equipment provided by the invention.

Detailed description of the invention

Below in conjunction with Figure of description and specific embodiment, the present invention is described in detail.

As it is shown in figure 1, the system realizing PTN device platform forward compatibility MSTP equipment provided by the invention,

Include at PTN device platform end: signal decomposition module 10, SAToP (Structure-AgnosticTDMoverPacket, destructuring emulates) sending module 20, CEP (CircuitEmulationoverPacket, circuit simulation) sending module 30, ethernet frame package module 40 and ethernet frame sending module 50;

Every road PDH (PlesiochronousDigitalHierarchy that PTN device platform is received by signal decomposition module 10, PDH) signal or SDH signal decompose, obtain PDH signal payload E1/T1/E3/T3 or SDH signal payload VC12/VC4, and PDH signal payload E1/T1/E3/T3 is sent to SAToP sending module 20, SDH signal payload VC12/VC4 is sent to CEP sending module 30;

SAToP sending module 20, continuous print PDH signal payload E1/T1/E3/T3 is cut into the PDH payload data section of regular length by the length according to system requirements according to SAToP agreement, the PDH payload data section on Bing Weimei road, plus FixedRTP frame head and SAToP control word, obtains the SAToP frame being payload with the section of PDH payload data;

The SDH payload data that continuous print SDH signal payload VC12/VC4 is cut into regular length according to CEP agreement is cut into slices by CEP sending module 30 according to the length of system requirements, the SDH payload data section of Bing Weimei road, plus FixedRTP frame head and CEPHeader (CEP agreement frame head), obtains the CEP frame being payload with the section of SDH payload data;

Ethernet frame package module 40 is SAToP frame or CEP frame interpolation MPLS/VLAN mark, the corresponding payload E1/T1/E3/T3/VC4/VC12 passage of each MPLS/VLAN mark, is packaged into SAToP or CEP ethernet frame composition ethernet frame;

Ethernet frame sending module 50 is by being sent to opposite end based on the exchange network of ethernet frame by packaged ethernet frame;

Include in opposite end: ethernet frame receiver module 60, SAToP receiver module 70, CEP receiver module 80 and signal recombination module 90;

SAToP or the CEP ethernet frame of reception is sent respectively to corresponding SAToP receiver module or CEP receiver module by ethernet frame receiver module 60;

SAToP receiver module 70 restore from SAToP ethernet frame PDH payload data section, and according to reduction sequence by PDH payload data section regroup generation continuous print PDH signal payload E1/T1/E3/T3;

CEP receiver module 80 restore from the ethernet frame of CEP frame format SDH payload data section, and according to reduction sequence by SDH payload data section regroup generation continuous print SDH signal payload VC12/VC-4;

The continuous print PDH signal payload E1/T1/E3/T3 or SDH signal payload VC12/VC-4 of restructuring are reduced into PDH signal or SDH signal by signal recombination module 90.

In the present invention, SAToP frame format is made up of LSP (MPLS)/PW (MPLS) LabelStack (label switched path/pseudo-wire label stacking), SAToP control word, FixedRTP frame head and E1/T/1/E3/T3 data slicer, specific as follows:

Wherein, the frame format of SAToPControlWord (SAToP control word) is:

Wherein,

Lbit is alarm indication bit, and Lbit set represents that the TDM payload in bag is invalid, when opposite end receives the bag that Lbit is 1, can send complete " 1 " to corresponding TDM port;

Rbit is remote bug indication bit, and Rbit puts 1 expression far-end receiving and loses;

RSVandFRG is reserved and segmentation bits, and sender must be set to 0, and recipient must ignore this bit;

Length (LEN) [0:5] is length field, if not 0, it indicates that the length of SAToP frame head; If employing RTP frame head, add the length of this RTP frame head length and load, and this length total value less than or equal to 64 byte time, length field must be set to actual value, is otherwise set to 0;

SequenceNumber [0:15] is bag sequence number, often sends a data slicer and is incremented by from 0 to 0xFFFF circulation, and opposite end can detect whether packet loss and according to this to the bag rearrangement received.

FixedRTPHeader (FixedRTP frame head) frame format is defined as:

Wherein:

V is version number, it is necessary to arrange 2;

P is that filling bit must be set to 0 by sender, and recipient must ignore this bit;

X is definition extended bit, it is necessary to be set to 0 by sender, and recipient must ignore this bit;

CC is effect source count bits, it is necessary to be set to 0 by sender, and recipient must ignore this bit;

M is identification bit, it is necessary to be set to 0 by sender, and recipient must ignore this bit;

PT [0:6] is Payloadtype (payload type), and the value of PT by the PW dynamic value range assignment in each direction, should can use same PT value between different CEPPW and direction;

SequenceNumber [0:15] is bag sequence number, often sends a circulation wrapped from 0 to 0xFFFF and is incremented by, and opposite end can detect whether packet loss and according to this to the bag rearrangement received, and this value is identical with the sequence number value in control word;

Timestamp [0:31] is timestamp value, is used for carrying timing information;

SSRC [0:31] is synchronisation source, can be used for detecting incorrect link.

In the present invention, CEP frame format is:

Wherein, the frame format of CEPHeader (CEP agreement frame head) is:

Wherein,

Lbit is alarm indication bit, and L bit set represents that the TDM payload in bag is invalid. When opposite end receives the bag that L bit is 1, complete " 1 " can be sent to corresponding TDM port;

Rbit is remote bug indication bit, and R bit is put 1 expression far-end receiving and lost;

NandPbits, pointer pays adjustment and positive justification indication bit, and these bits are used for clearly relaying the Pointer Justification Event of the negative, positive through PSN, it is optional for using N and P bit, without use, N and P bit must be set to 0, and N and P bit arranges description as shown in table 1.

Table 1:N and P bit arrange description.

FRG is segmentation bits, and sender must be set to 0 in the present invention, and recipient must ignore this bit.

Length [0:5] is length field, if not 0, then indicate the length of CEP head, if employing RTP head, add this length, length plus load. when CEP head length is plus loaded length, add RTP head length, time total value is less than or equal to 64 byte, length field must be set to actual value, is otherwise necessary for being set to 0;

SequenceNumber [0:15], bag sequence number, often send a circulation wrapped from 0 to 0xFFFF and be incremented by, opposite end can detect whether packet loss and according to this to the bag rearrangement received;

StructurePointer [0:11], structured fingers value. Structured fingers must comprise the biasing of the first character joint of the SONET structure in payload package, emulates for SPE, and structured fingers is positioned at the j1 byte of CEP bag, emulates for VT, and structured fingers is positioned at the V5 byte of bag; Structured fingers value scope, from 0 to 0xFFE, 0 represents first character joint followed by CEP head here, and when data slicer does not carry J1 or V5 byte time, structured fingers must be set to 0xFFF; Any pointer of accessory circuit changes (new data flag (NDF) event) can change the SONET configuration biases in CEP bag, thus the value of the pointer that restructures;

Reserved is reserved field, and sender must be set to 0, and recipient must ignore this bit.

As in figure 2 it is shown, the method realizing PTN device platform forward compatibility MSTP equipment provided by the invention, comprise the following steps:

Step A100, the every road PDH signal received by PTN device platform or SDH signal decomposition are continuous print PDH signal payload E1/T1/E3/T3 or SDH signal payload VC12/VC-4;

Step A200, according to the length of system requirements by continuous print PDH signal payload E1/T1/E3/T3 or SDH signal payload VC12/VC-4, it is cut into PDH payload or the section of SDH payload data of regular length according to RFC4553 (SAToP) agreement or RFC4842 (CEP) agreement, and cuts into slices as payload composition SAToP frame or CEP frame with PDH payload or SDH payload data respectively;

Step A300, add MPLS/VLAN mark for SAToP frame or CEP frame, the corresponding payload E1/T1/E3/T3/VC4/VC12 passage of each MPLS/VLAN mark, it is packaged into SAToP or CEP ethernet frame; The form of the ethernet frame with MPLS/VLAN mark is as shown in table 2, including:

Source address;

Destination address;

TPID (TagProtocalIdentifier, tag protocol identifier)+VLAN;

Ethertype (ethernet frame type);

SAToP frame format or CEP frame format (i.e. LSP (LabelSwitchedPath, label switched path) or the VC12/VC4 data slicer of the E1/T/1/E3/T3 data slicer of PW (PseudoWire, pseudo-wire), the SAToPControlWord of corresponding E1/T1/E3/T3 business or CEPHeader, FixedRTPHeader of corresponding VC12/VC4 business and corresponding SAToP agreement or corresponding CEP agreement;

FCS (FrameCheckSequence, Frame Check Sequence);

Wherein, TPID value is expressed as 0x8100 with 16 systems, the channel number one_to_one corresponding of VLAN value and LSP/PW definition, the Ethertype value of ethernet frame is expressed as 0x8847 with 16 systems, LSP/PW value represents with 16 systems, and each LSP/PW value and E1/T1/E3/T3/VC12/VC4 signalling channel one_to_one corresponding.

The form of table 2:SAToP or CEP ethernet frame.

Step A400, by based on the exchange network of ethernet frame, packaged SAToP or CEP ethernet frame realizes arbitrarily exchange in based on the distributed switching architecture data equipment of Ethernet bag, any single-deck/the arbitrary port in this equipment can be exchanged to, thus being sent to opposite end.

SAToP or the CEP ethernet frame received is forwarded to SAToP receiver module or the CEP receiver module of its correspondence by step A500, opposite end, continuous P DH signal payload or SDH signal payload is recovered by ethernet frame respectively by SAToP receiver module or CEP receiver module, PDH signal or SDH signal is obtained then through signal recombination module, wherein, different PDH signals or SDH signalling channel are identified by MPLS/VLAN to be distinguished.

In the present invention, the pass-through mode of SAToP or CEP ethernet frame is clean culture, multicast and broadcast, and the selection of the pass-through mode of SAToP or CEP ethernet frame is determined by destination address.

The prior art that the content not being described in detail in description is known to the skilled person; the embodiment of the present invention can be carried out various modifications and variations by those skilled in the art; if these amendments and modification are within the scope of the claims in the present invention and equivalent technologies thereof, then these amendments and modification are also within protection scope of the present invention.

Claims (10)

1. the system realizing PTN device platform forward compatibility MSTP equipment, it is characterised in that

Include at PTN device platform end:

Signal decomposition module, the every road PDH signal or the SDH signals that receive PTN device platform decompose, it is thus achieved that PDH signal payload E1/T1/E3/T3 or SDH signal payload VC12/VC4, and send;

SAToP sending module, PDH signal payload E1/T1/E3/T3 described in continuous print is cut into the PDH payload data section of regular length by the length according to system requirements, the PDH payload data section of Bing Weimei road, plus FixedRTP frame head and SAToP control word, obtains the SAToP frame being payload with the section of described PDH payload data;

CEP sending module, SDH signal payload VC12/VC4 described in continuous print is cut into the SDH payload data section of regular length by the length according to system requirements, the SDH payload data section of Bing Weimei road, plus FixedRTP frame head and CEP agreement frame head, obtains the CEP frame being payload with the section of described SDH payload data;

Ethernet frame package module, adds MPLS/VLAN mark, the corresponding payload E1/T1/E3/T3/VC4/VC12 passage of each MPLS/VLAN mark for described SAToP frame or CEP frame, is packaged into SAToP or CEP ethernet frame;

Ethernet frame sending module, by being sent to opposite end based on the exchange network of ethernet frame by packaged ethernet frame;

Include in opposite end:

Ethernet frame receiver module, forwards respectively accordingly by described SAToP or the CEP ethernet frame received;

SAToP receiver module, restores the section of PDH payload data from described SAToP ethernet frame, and described PDH payload data slice graph display is generated continuous print PDH signal payload E1/T1/E3/T3;

CEP receiver module, restores the section of SDH payload data from described CEP ethernet frame, and described SDH payload data slice graph display is generated continuous print SDH signal payload VC12/VC-4;

Signal recombination module, is reduced into PDH signal or SDH signal by the continuous print PDH signal payload E1/T1/E3/T3 of restructuring or SDH signal payload VC12/VC-4.

2. realize the system of PTN device platform forward compatibility MSTP equipment as claimed in claim 1, it is characterized in that, described SAToP ethernet frame format is made up of label switched path or pseudo-wire label stacking, SAToP control word, FixedRTP frame head and E1/T/1/E3/T3 data slicer.

3. realize the system of PTN device platform forward compatibility MSTP equipment as claimed in claim 1, it is characterized in that, described CEP ethernet frame format is made up of label switched path or pseudo-wire label stacking, CEP agreement frame head, FixedRTP frame head and VC12/VC4 data slicer.

4. realize the system of PTN device platform forward compatibility MSTP equipment as claimed in claim 2 or claim 3, it is characterised in that the form of described FixedRTP frame head includes:

Version number V, it is necessary to arrange 2;

Filling bit P, sender must be set to 0, and recipient must ignore this bit;

Definition extended bit X, sender must be set to 0, and recipient must ignore this bit;

Effect source count bits CC, sender must be set to 0, and recipient must ignore this bit;

Identification bit M, it is necessary to be set to 0 by sender, and recipient must ignore this bit;

Payload type PT [0:6], the value of PT by the PW dynamic value range assignment in each direction, should can use same PT value between different CEPPW and direction;

Bag sequence number SequenceNumber [0:15], often sends a circulation wrapped from 0 to 0xFFFF and is incremented by, and opposite end can detect whether packet loss and according to this to the bag rearrangement received, and this value is identical with the sequence number value in control word;

Timestamp value Timestamp [0:31], is used for carrying timing information;

Synchronisation source SSRC [0:31], can be used for detecting incorrect link.

5. realize the system of PTN device platform forward compatibility MSTP equipment as claimed in claim 2, it is characterised in that described SAToP control word is made up of following field:

Lbit, for alarm indication bit, Lbit set represents that the TDM payload in bag is invalid, when opposite end receives the bag that Lbit is 1, can send complete " 1 " to corresponding TDM port;

Rbit, for remote bug indication bit, Rbit puts 1 expression far-end receiving and loses;

RSVandFRG, for reserved and segmentation bits, sender must be set to 0, and recipient must ignore this bit;

Length [0:5], for length field, if not 0, it indicates that the length of SAToP frame head; If employing RTP frame head, add the length of this RTP frame head length and load, and if this length total value less than or equal to 64 byte time, length field must be set to actual value, is otherwise set to 0;

SequenceNumber [0:15], for bag sequence number, often one data slicer of transmission is incremented by from 0 to 0xFFFF circulation, and opposite end can detect whether packet loss and according to this to the bag rearrangement received.

6. realize the system of PTN device platform forward compatibility MSTP equipment as claimed in claim 3, it is characterised in that CEPHeader is made up of following field:

Lbit, for alarm indication bit, Lbit set represents that the TDM payload in data slicer is invalid, when opposite end receives the data slicer that Lbit is 1, can send complete " 1 " to corresponding TDM port;

Rbit, for remote bug indication bit, Rbit set represents that far-end receiving is lost;

NandPbits, for pointer negative justification and positive justification indication bit, this bit is used for clearly relaying the Pointer Justification Event of the negative, positive through PSN, and it is optional for using N and P bit, and without use, N and P bit must be set to 0;

FRG, for segmentation bits, sender must be set to 0, and recipient must ignore this bit;

Length [0:5], for length field, if not 0, it indicates that the length of CEP frame head; If employing RTP frame head, add the length of this RTP frame head length and load, and if the total value of this length less than or equal to 64 byte time, length field must be set to actual value, is otherwise necessary for being set to 0;

SequenceNumber [0:15], for bag sequence number, often one data slicer of transmission is incremented by from 0 to 0xFFFF circulation, and opposite end can detect whether packet loss and according to this to the bag rearrangement received;

StructurePointer [0:11], for structured fingers value, structured fingers must comprise the biasing of the first character joint of the SONET structure in payload package, SPE is emulated, structured fingers is positioned at the j1 byte of CEP data slicer, emulating for VT, structured fingers is positioned at the V5 byte of data slicer; Structured fingers value scope from " 0 " to " 0xFFE ", described " 0 " represents first character and saves followed by CEP frame head, and when data slicer does not carry J1 or V5 byte time, structured fingers must be set to 0xFFF;

Reserved, for reserved field, sender must be set to 0, and recipient must ignore this bit.

7. realize the system of PTN device platform forward compatibility MSTP equipment as claimed in claim 6, it is characterised in that NandPbits arrange description as follows:

When N, P are set to 0, pointer-free adjustment is described;

When N, P are set to 1, Loss Of Pointer alarm is described;

When N be set to 0, P be set to 1 time, positive pointer regulation is described;

When N be set to 1, P be set to 0 time, negative pointer regulation is described.

8. realize the system of PTN device platform forward compatibility MSTP equipment as claimed in claim 2 or claim 3, it is characterised in that the form of described SAToP or CEP ethernet frame includes:

Source address;

Destination address;

TPID tag protocol identifier+VLAN;

Ethernet frame type;

SAToP frame format or CEP frame format;

Frame Check Sequence.

9. realize the system of PTN device platform forward compatibility MSTP equipment as claimed in claim 8, it is characterised in that

TPID tag protocol identifier value is expressed as 0x8100 with 16 systems;

The channel number one_to_one corresponding of VLAN value and label switched path definition;

Ethernet frame type value is expressed as 0x8847 with 16 systems;

Label switched path value represents with 16 systems, and each label switched path value and E1/T1/E3/T3/VC12/VC4 signalling channel one_to_one corresponding.

10. the method realizing PTN device platform forward compatibility MSTP equipment, it is characterised in that comprise the following steps:

Step A100, the every road PDH signal received by PTN device platform or SDH signal decomposition are continuous print PDH signal payload E1/T1/E3/T3 or SDH signal payload VC12/VC-4;

Step A200, according to the length of system requirements by continuous print PDH signal payload E1/T1/E3/T3 or SDH signal payload VC12/VC-4, it is cut into PDH payload or the section of SDH payload data of regular length according to SAToP agreement or CEP agreement, and forms SAToP frame or CEP frame for payload to cut into slices containing PDH payload or SDH payload data respectively;

Step A300, add MPLS/VLAN mark for SAToP frame or CEP frame, the corresponding payload E1/T1/E3/T3/VC4/VC12 passage of each MPLS/VLAN mark, it is packaged into SAToP or CEP ethernet frame;

Step A400, by based on the exchange network of ethernet frame, packaged SAToP or CEP ethernet frame being delivered to opposite end;

SAToP or the CEP ethernet frame of reception is distributed to corresponding SAToP receiver module or CEP receiver module by step A500, opposite end, recover continuous P DH signal payload or SDH signal payload respectively, and obtain PDH signal or SDH signal through signal restructuring, wherein, different PDH signals or SDH signalling channel are identified by MPLS/VLAN to be distinguished.