CN112565943A

CN112565943A - DCN processing method and system for packet and optical transport network fusion product

Info

Publication number: CN112565943A
Application number: CN202011473948.0A
Authority: CN
Inventors: 马小云
Original assignee: Anhui Wantong Post And Telecommunications Co ltd
Current assignee: Anhui Wantong Post And Telecommunications Co ltd
Priority date: 2020-12-15
Filing date: 2020-12-15
Publication date: 2021-03-26
Anticipated expiration: 2040-12-15
Also published as: CN112565943B

Abstract

The invention discloses a DCN processing system of a packet and optical transport network fusion product, which comprises a packet control plane, a packet forwarding plane and an optical transport network forwarding plane. The invention also discloses a processing method of the file processing system. The invention uses the corresponding virtual port of the OTN generated on the grouping device, and connects the PTN and the OTN with different network forwarding characteristics together through the corresponding relation generated by the grouping control forwarding and the OTN, thereby achieving the purpose of transmitting the control information.

Description

DCN processing method and system for packet and optical transport network fusion product

Technical Field

The invention relates to the technical field of network communication, in particular to a DCN processing method and a DCN processing system for a packet and optical transport network convergence product.

Background

A Packet Transport Network (PTN) is a Packet-switched core Packet-oriented Transport Network (pdn) oriented to Packet data services. PTN is also a packet forwarding based, connection-oriented multi-service delivery technique.

The Optical Transport Network (OTN) technology is a product of the compromise between an electric network and a full optical network, and the powerful and perfect OAM & P concept and function of SDH are transplanted to a WDM optical network, so that the defects of the existing WDM system in the aspects of performance monitoring, maintenance and management are effectively overcome.

As mobile services enter the 4G and 5G era, a large amount of information data is required to be sent from one place to another every day. The existing information transportation modes SDH, WDM, OTN and PTN are all single data transmission modes, which can not simultaneously meet the requirements of high-speed TDM special line and packet switching for all-service transmission, forcing people to propose a new fusion information-bearing scheme POTN.

A Data Communication Network (DCN) refers to a network that provides a transport path for the communication of management information and control information within and among a transport plane, a control plane, and a management plane. The DCN is a network supporting functions of a first layer (physical layer), a second layer (data link layer) and a third layer (network layer) in a seven-layer protocol stack of the network, and mainly carries management information and distributed signaling messages. In a public data communication network there are three forms of data transmission services, circuit switched, packet switched and leased circuit.

The packet and optical transport network convergence device also needs to manage the device through an existing deployed management and control system. For such a requirement, it is necessary to open the path between the management system and the device, the management information of the optical transport network is usually delivered by means of GCC overhead, and the packet network is based on packet forwarding. Therefore, it is necessary to provide a DCN processing method and system for a packet and optical transport network convergence product.

Disclosure of Invention

The DCN processing method and system for the packet and optical transport network fusion product can solve the problem of communication between POTN equipment and the existing packet management and control system.

In order to achieve the purpose, the invention adopts the following technical scheme:

a DCN processing method of a packet and optical transport network convergence product includes the following steps:

when the information is sent to the optical port connection information of the optical transmission network from the fusion equipment:

step S100, generating a virtual PPP interface corresponding to an optical port on a CPU, generating related forwarding table item information and optical transport network information, issuing a protocol message needing to be connected, and packaging a special ETH header and a header of a packet switching chip to the packet switching chip;

step S200, the packet switching chip receives the message, the analysis head is the message sent to the port connected with the FPGA, and the message head is stripped off to send the port to the FPGA in an oriented manner;

step S300, the FPGA analyzes a port sent to an optical transport network according to message header information carried in a message, then strips off a special header, encapsulates the original PPP message header, recovers the original PPP message, encapsulates the original PPP message into an HDLC format, and sends a frame to an outlet of the optical transport network in a GCC overhead mode;

when receiving the connection information sent to the fusion equipment from the optical port of the optical transmission network:

step S400, the FPGA resolves the frame information into GCC overhead and then restores the GCC overhead into a message form, then carries out HDLC format decapsulation, further restores the GCC overhead into an original PPP message, strips off the PPP message header and then encapsulates a special ETH header including input port information, and sends the message to a packet switching chip;

step S500, the packet switching chip receives the message, the analysis is the message received from the FPGA, and the message is sent to a port connected with the CPU after being added with a corresponding head;

step S600, the CPU receives the message which is known to be from the FPGA by the head of the message analysis packet switching chip, and then analyzes the special ETH head to indicate that the protocol message needs to be uploaded to the corresponding virtual PPP interface.

Further, the step S100 specifically includes:

step S101: whether an optical port exists in the OTN;

step S102: if not, the process is ended; if the DCN PPP virtual interface exists, performing combined operation according to the port type, the slot position number of the port and the port number to obtain an index of the DCN PPP virtual interface;

step S103: according to the DCN virtual interface index, through configuration management, the control plane generates a corresponding DCN PPP virtual interface and sends a link establishment protocol message corresponding to the virtual interface;

step S104: the forwarding plane receives the message and finds out the real exit according to the generated port conversion table item;

step S105: in order to facilitate the FPGA to conveniently recognize the control message, a special ETH header is packaged to identify the message, wherein the message comprises a special MAC and a layer of special VLAN 4094 indicates a DCN information message;

step S106: then packaging the output port into a message in a VLAN form;

step S107: and packaging a layer of TAG to identify the packet switching chip and sending the message to the FPGA.

Further, the step S300 specifically includes:

step S301: whether the message received by the FPGA is an appointed special ETH MAC header or not;

step S302: if not, discarding the message, if so, extracting special ETH header VLAN information for enqueuing according to the priority;

step S303: judging whether the scheduling can be obtained;

step S304: if not, waiting in the cache, and if so, stripping off the special ETH head;

step S305: the head of the original PPP message is encapsulated and restored into the original PPP message;

step S306: then, performing message encapsulation in an HDLC format;

step S307: inserting the encapsulated packet into the GCC overhead includes

Step S308: will be sent in frames from the corresponding optical ports onto the optical transport network.

Further, in step S400, the information of the ingress port is VLAN information and VLAN 4094 representing a DCN packet.

Further, the step S600 specifically includes:

step S601: analyzing and stripping the message TAG information, and judging whether the message is sent from the FPGA;

step S602: if not, processing according to the common message flow, if yes, entering into OTN DCN processing flow;

step S603: judging whether the head is a special ETH MAC head;

step S604: if not, packet loss is carried out, if so, the encapsulated VLAN information is further analyzed, and the slot port number of the OTN interface is extracted;

step S605: searching a forwarding table item, and converting a DCN PPP virtual interface corresponding to the interface;

step S606: stripping off a special ETH head, packaging a PPP head, and restoring an original PPP message;

step S607: and encapsulating the contents such as port information and the like required by the control plane into an uploading header, and uploading the uploading header and the message to the control plane.

A DCN processing system of a packet and optical transport network fusion product comprises a packet control plane, a packet forwarding plane and an optical transport network forwarding plane;

the processing of the packet control plane comprises generation of an OTN DCN interface, processing of a PPP protocol module, configuration of a DHCP function, configuration of an OSPF protocol and routing processing;

generating a DCN virtual interface, wherein the DCN virtual interface is used for facilitating the management of each corresponding user by a management and control system;

PPP protocol module, which is used to set up link between two adjacent devices;

the DHCP function is used for allocating addresses in the user address pool to a remote management and control system as required;

the OSPF protocol module is used for announcing the route and opening a path between the management and control systems;

the routing module is used for forwarding the message to a required destination address;

the packet forwarding plane comprises a forwarding table module, a multi-core CPU forwarding module and a packet switching chip module; the forwarding table module is generated by a control plane;

the multi-core CPU forwarding module executes a search action, and mainly comprises conversion among ports;

the packet switching chip module is responsible for information transmission between the multi-core CPU module and the optical transmission network;

the optical transmission network forwarding plane is mainly an FPGA module;

the FPGA is responsible for enqueuing the messages according to the priority and carrying out scheduling processing, and the dequeued messages are converted into a GCC overhead mode after being subjected to HDLC packaging and are sent to the OTN from an optical port in an optical network frame format; or receiving the corresponding frame from the OTN network optical port reversely, resolving GCC overhead, reducing the GCC overhead into a message, then performing HDLC decapsulation, finally encapsulating the message into an appointed message and sending the appointed message to the packet module.

Compared with the prior art, the invention uses the corresponding virtual port of the OTN network generated on the grouping equipment, and connects the PTN and the OTN with different network forwarding characteristics through the corresponding relation generated by the grouping control forwarding and the OTN network, thereby achieving the purpose of transmitting the control information.

Drawings

FIG. 1 is a flow chart of the method of the present invention;

FIG. 2 is a schematic diagram of the hardware architecture of the present invention;

FIG. 3 is a schematic diagram illustrating the management and control of the present invention in the whole network;

FIG. 4 is a flow chart of the CPU processing from the CPU to the packet switch chip according to the present invention;

FIG. 5 is a flow chart of the packet switch chip processing to the FPGA of the present invention;

FIG. 6 is a flow chart of the FPGA processing from the FPGA to the optical network port of the present invention;

FIG. 7 is a flow chart of FPGA processing from an optical network port to an FPGA of the present invention;

FIG. 8 is a flow chart of the packet switch chip processing from the FPGA to the packet switch chip of the present invention;

FIG. 9 is a flow chart of the CPU processing from the packet switch chip to the CPU of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention.

As shown in fig. 1, the DCN processing method for a packet and optical transport network convergence product according to this embodiment includes:

step S100, generating a virtual PPP interface corresponding to an optical port on a CPU, generating related forwarding table item information and optical transport network information, issuing messages such as protocols and the like needing to be connected, and packaging a special ETH head and a head of a packet switching chip to the packet switching chip;

step S300, the FPGA analyzes a port sent to the optical transport network according to message header information carried in the message, then strips off a special header, encapsulates the original PPP message header, recovers the original PPP message, encapsulates the original PPP message into an HDLC format, and sends a frame to an outlet of the optical transport network in a GCC overhead form.

As shown in fig. 2, it is a connection diagram of the hardware structure of the present invention:

the packet layer is composed of CPU and packet switching chip, and the optical transmission network layer is mainly realized by FPGA. The multi-core CPU is used as a control surface and a forwarding core, bears the operation of the whole control surface software system, generates various table items required by a forwarding surface, and forwards the table items according to the forwarding requirement. The packet switching chip can switch and forward the message to the corresponding device according to the requirement, and plays a key and flexible role in starting and ending. The FPGA is an important device of the optical transport network, and can receive and send frame signals of the optical transport network, perform overhead processing, and convert between messages and frame formats.

As shown in fig. 3, a network diagram of the whole management and control system is shown:

the access OTN is hung under the local side OTN (including hub), the local side OTN firstly establishes a control connection with a control system, and then the access OTN establishes a control connection with the control system. A special management network (composed of Ethernet switches and routers) is deployed between the local side OTN and the domain management and control system, and the access is routed by using the OSPFv2 protocol. No special management network is deployed between the access OTN and the local OTN, and only the management and control information can be transmitted through the service network.

The GCC (general Communication channel) overhead of the OTN is used as a basic physical channel between the access OTN and the local side OTN, the PPP protocol message is encoded by the HDLC and mapped into the GCC overhead to form a data link layer format of the PPPoverHDLC and is transmitted to the opposite side, and the opposite side restores the PPP protocol message by demapping and decoding.

After the access OTN and the local side OTN establish a PPP link, a DHCP request (discover/request) is initiated. And the local side OTN is used as a DHCP Relay, and the DHCP protocol message is forwarded between the access OTN and the management and control system based on the management network. The management and control system responds to the DHCP request, allocates an IP address according to a certain planning strategy and generates a DHCP response (offer/ack). Meanwhile, the DHCP ack also carries the management and control system address through DNS Option.

To further understand the flow of the steps for forwarding the data packet in the device provided by the embodiment of the present invention, the following description will be made in detail.

As shown in fig. 4, is the flow from the CPU to the packet switch chip:

step S101: whether an optical port exists in the OTN;

step S106: then packaging the output port into a message in a VLAN form;

As shown in fig. 5, is a flow from the packet switch chip to the FPGA:

step S201: the packet switching chip receives the message, analyzes the tag carried by the message and strips the tag;

step S202: whether the output port is a port connected with the FPGA or not;

step S203: if so, to the FPGA, and if not, to other devices.

As shown in fig. 6, it is a flow from the FPGA to the optical network port:

step S303: judging whether the scheduling can be obtained;

step S306: then, performing message encapsulation in an HDLC format;

step S307: inserting the encapsulated message into GCC overhead:

As shown in fig. 7, it is the flow from the FPGA to the packet switch chip:

step S401: the FPGA receives a corresponding frame from the optical transport network and extracts GCC overhead:

step S402: reducing GCC overhead into a message form;

step S403: performing HDLC decapsulation on the message;

step S404: stripping off the PPP head of the PPP message;

step S405: and packaging a special ETH header appointed with the CPU, including VLAN information of an input port and VLAN 4094 representing a DCN message, and sending the message to the packet switching chip.

As shown in fig. 8, is the flow of the packet switched chip to the CPU:

step S501: the packet switching chip judges whether the input port is a port connected with the FPGA;

step S502: if not, sending to other ports; if so, sending the message to a destination port which is a port connected with the CPU;

step S503: the packet switching chip packages TAG information interacted with the CPU, contains the information of an input port, and sends the message to the CPU.

As shown in fig. 9, it is the flow from the CPU to the control plane:

step S603: judging whether the head is a special ETH MAC head;

The above steps complete DCN communication of the packet and optical transport network convergence product.

The DCN processing system comprises a packet control plane, a packet forwarding plane and an optical transport network forwarding plane.

And the processing of the packet control plane comprises generation of an OTN DCN interface, processing of a PPP protocol module, configuration of a DHCP function, configuration of an OSPF protocol and routing processing. And generating a DCN virtual interface, wherein the DCN virtual interface is used for conveniently managing each corresponding user by a management and control system. PPP protocol module, which is used to set up link between two adjacent devices. And a DHCP function, wherein a management and control system for a remote end can allocate addresses in the user address pool as required. And the OSPF protocol module is used for announcing the route and opening a passage between the management and control systems. And the routing module is used for forwarding the message to a required destination address.

The packet forwarding plane is divided into a forwarding table module, a multi-core CPU forwarding module and a packet switching chip module. Wherein, the forwarding table module is generated by a control plane; the multi-core CPU forwarding module executes a search action, and mainly comprises conversion among ports; the packet switching chip module is responsible for information transmission between the multi-core CPU module and the optical transport network. The multi-core CPU forwarding module is divided into a mode of receiving a message from a network port of the OTN to send to a control surface, a mode of sending the message from the control surface to forward the message to the OTN network port, and a mode of forwarding between the OTN network port and the PTN network port. Receiving a message from a network port of the OTN and sending the message to a control surface for processing, analyzing and identifying the message received from the network port and a source single-board port by a forwarding plane packet receiving module, searching a corresponding port conversion table according to needs, converting the port conversion table out a DCN interface, and sending the message to the control surface; the method comprises the steps that a control surface issues a message to be forwarded to a forwarding plane OTN network port, a single board port corresponding to a DCN interface needs to be searched according to a port conversion table, and then the message is sent to the corresponding network port through packaging a specific message format; the forwarding between the OTN network port and the PTN network port is also analyzed firstly and then directly forwarded to another interface in a route searching mode, and a specific message is encapsulated and sent out.

The optical transport network forwarding plane is mainly an FPGA module. The FPGA is responsible for enqueuing the messages according to the priority and carrying out scheduling processing, and the dequeued messages are converted into a GCC overhead mode after being subjected to HDLC packaging and are sent to the OTN from an optical port in an optical network frame format; or receiving the corresponding frame from the OTN network optical port reversely, resolving GCC overhead, reducing the GCC overhead into a message, then performing HDLC decapsulation, finally encapsulating the message into an appointed message and sending the appointed message to the packet module.

Therefore, the DCN processing method and system for realizing the fusion product of the packet and the optical transport network meet the flexible and efficient network requirements and solve the problem of communication with the existing deployed management and control system.

To sum up, the embodiment of the present invention creates a virtual interface of an interface corresponding to an optical transport network on a packet layer, and transmits a packet message to the optical transport network through a packet switching chip to be sent to an OTN network in a GCC overhead form, or extracts information of the optical transport network through the GCC overhead and converts the extracted information into a packet message to be transmitted to the packet layer, so as to achieve the purpose of communicating a packet and optical transport network fusion product with an existing deployed management and control system, and meet the requirement of a management and control network device.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A DCN processing method for a packet and optical transport network convergence product is characterized in that: the method comprises the following steps:

2. The DCN processing method of a packet and optical transport network convergence product according to claim 1, wherein: the step S100 specifically includes:

step S101: whether an optical port exists in the OTN;

step S106: then packaging the output port into a message in a VLAN form;

3. The DCN processing method of a packet and optical transport network convergence product according to claim 1, wherein: the step S300 specifically includes:

step S303: judging whether the scheduling can be obtained;

step S306: then, performing message encapsulation in an HDLC format;

step S307: inserting the encapsulated packet into the GCC overhead includes

4. The DCN processing method of a packet and optical transport network convergence product according to claim 1, wherein: in the step S400, the first step is performed,

the information of the input port is VLAN information and VLAN 4094 representing DCN message.

5. The DCN processing method of a packet and optical transport network convergence product according to claim 1, wherein: the step S600 specifically includes:

step S603: judging whether the head is a special ETH MAC head;

6. A DCN processing system for a packet and optical transport network convergence product, comprising: the optical transmission network comprises a packet control plane, a packet forwarding plane and an optical transmission network forwarding plane;

PPP protocol module, which is used to set up link between two adjacent devices;

the optical transmission network forwarding plane is mainly an FPGA module;