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HUAWEI OptiX OSN 8800 T64/T32 Intelligent Optical Transport Platform. Product Description - part 16

Application 1: Time transmission based on IEEE 1588v2-compliant frequency

synchronization and phase synchronization

As shown in Figure 5-45, the other device (such as the OptiX PTN device) obtains frequency

and phase signals from the BITS device and transmits the frequency and phase signals to the

connected OptiX OSN 8800 on the OTN network. On the other side of the OTN network, another

OptiX OSN 8800 transmits the frequency and phase signals to the two other devices (such as

OptiX PTN devices or OptiX OSN 1800) over GE services. After receiving the frequency and

phase signals, the two other devices (such as OptiX PTN devices or OptiX OSN 1800) send the

frequency and phase signals to the Node Bs over GE services. For details about the

configurations, see Example Description.

Figure 5-45 IEEE 1588v2-compliant time transmission over GE services (using OSC channels

over the OTN network)

Frequency/Phase Sources

Transport Network

Base Stations

East

West

GE

Slave

BITS

West

GE

A

East

GE

Master

E

OTN Network

BITS

B

D

F

East

C

West

GE

West

East

Optical Cables

Cables

1588v2 frequency synchronization route

1588v2 phase synchronization route

Sites

Direction

Board

1588v2 frequency synchronization protection route

East

1-11ST2-1

1588v2 phase synchronization protection route

A,B,C,D

West

1-11ST2-2

OptiX OTN

BITS

Other devices

Node B

product series

Figure 5-46 shows an example in which frequency and phase signals are received using 2M

external clocks and 1PPS+TOD and phase synchronization is implemented using the second

method (IEEE 1588v2-compliant frequency synchronization + IEEE 1588v2-compliant phase

synchronization).

Application 2: Time transmission based on physical clock frequency synchronization and

IEEE 1588v2-compliant phase synchronization

As shown in Figure 5-46, on one side of the OTN network two OptiX OSN 8800 obtain 2M

clock signals and 1PPS+TOD time signals from the master and slave BITS devices and send the

frequency and phase signals to other OptiX OSN 8800 on the network. On the other side of the

OTN network, after processing the frequency and phase signals using the ESC boards, the egress

OptiX OSN 8800 sends the frequency and phase signals to the connected other devices (such as

OptiX PTN devices or OptiX OSN 1800). Then, the other devices (such as OptiX PTN devices

or OptiX OSN 1800) send the frequency and phase signals to the Node Bs through their 2M

external ports and external time ports (1PPS+TOD ports). For details about the configurations,

see Example Description.

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Figure 5-46 Physical clock frequency synchronization + IEEE 1588v2-compliant phase

synchronization using 2M clock and 1PPS+TOD ports (using ESC channels over the OTN

network)

Frequency/Phase Sources

Transport Network

Base Stations

2M/1PPS

East

West

+TOD

West

GE

A

East

E

E

B

OTN Network

D

2M/1PPS

F

+TOD

East

GE

C

West

West

East

Optical Cables

Cables

Physical synchronization route

1588v2 phase synchronization protection route

Sites

Direction

Board

Physical synchronization protection route

East

12-52ND2-1

1588v2 frequency synchronization protection route

A,B,C,D

West

12-52ND2-2

OptiX OTN

BITS

Other devices

Node B

product series

5.10 ASON Management

An automatically switched optical network (ASON) is a new-generation optical transmission

network.

With integration of SONET/SDH functionality, effective IP technology, large-capacity WDM/

OTN, and revolutionary network control software, ASON lays a foundation for flexible and

scalable next generation optical networks, which are easy to operate and manage, and less

expensive to operate.

Introducing ASON into WDM networks brings the following benefits:

l High reliability: Protection and restoration together improve network reliability and service

security.

l Easy to use: Network resources and topologies are easy to discover and end-to-end services

can be quickly created.

l Easy to manage: Trail resources are manageable and predictable, and services can be

automatically reverted to their original trails.

l Investment saving: A mesh network ensures higher resource usage and enables quick

expansion (plug-and-play).

l New service types: Service level agreement (SLA) ensures differentiated services.

WDM/OTN equipment is an effective service carrier. However, only the capability of carrying

services (on the transport plane) does not qualify WDM/OTN equipment as advanced and future-

oriented equipment, which also requires outstanding performance in bandwidth usage,

flexibility, manageability, maintainability, reliability, and protection capability. It has become

a trend to implement a control plane over the transport plane of the WDM/OTN equipment.

The limitations on the WDM/OTN equipment are removed after the ASON technology is

implemented on the WDM/OTN equipment. Because of the ASON technology, the WDM/OTN

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equipment features high reliability, flexibility, bandwidth utilization, maintainability, and

manageability and supports different service levels and quick deployment of services. Further,

the operability of a WDM/OTN network is highly improved because of the features supported

by the ASON technology, such as automatic discovery of resources, traffic engineering, dynamic

bandwidth adjustment, and interconnection and communication technologies.

In addition, the OptiX OSN 8800 is also capable of cross-connecting services at the SDH layer.

Therefore, WDM ASON equipment can be networked with WDM ASON equipment or SDH

ASON equipment to enable cross-connections at multiple granularities and multiple layers, as

shown in Figure 5-47.

Figure 5-47 Flexible networking and multi-layer service cross-connections

OptiX OSN 8800

OptiX OSN 8800

Wavelength

OptiX OSN 8800

OptiX OSN 8800

OptiX OSN 9500

ODUk

VCk

OptiX OSN 8800

OptiX OSN 7500

OptiX OSN 6800

OptiX OSN 3500

Wavelength Link

ODUk Link

VCk Link

5.11 Transmission of Network Management Information

There are three communication modes: HWECC, OSI over DCC, IP over DCC.

l HWECC: The management information is transmitted by using the HWECC protocol

sharing method.

l IP over DCC management information is transferred by using the IP protocol sharing

method.

l OSI over DCC: The management information is transferred by using the OSI protocol

sharing method.

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5.11.1 DCN Composition

DCNs are classified as internal and external DCNs.

Both the U2000 and NEs are nodes of a DCN. The DCN between the U2000 and NEs is called

the external DCN, and the DCN between NEs is called the internal DCN, as shown in Figure

5-48.

Figure 5-48 DCN composition

Primary

Secondary

NMS

NMS

External DCN

Internal DCN

NG WDM

Ethernet

Router

equipment

switch

Network

Fiber

cable

l External DCN

On an actual network, the U2000 and NEs may be located on different floors of a building,

in different buildings, or even in different cities. Hence, an external DCN that is comprised

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of the data communication equipment, such as LAN switches and routers, is required to

connect the U2000 and the NEs. As the external DCN involves knowledge of data

communication, no detailed description is provided in this document. The DCN mentioned

in this document refers to the internal DCN, unless otherwise specified.

l Internal DCN

On an internal DCN, the equipment supports the optical supervisory channel (OSC) and

the electrical supervisory channel (ESC) technologies to implement the DCN.

5.11.1.1 Optical Supervisory Channel Administration

The management information of the stations in the system is transmitted through the optical

supervisory channel (OSC).

Functions of the OSC

The optical supervisory channel (OSC) transmits the monitoring and management information

among the stations. The channel of the OSC is at 1491/1510/1511 nm.

The OSC boards include the HSC1, SC1, SC2 and ST2.

The OSC adopts CMI coding. If the signal rate is 2 Mbit/s before the coding, the signal rate is

4 Mbit/s after the coding. If the signal rate is 8 Mbit/s before the coding, the signal rate is 16

Mbit/s after the coding.

Working of the OSC

Figure 5-49 shows the signal flow of the OSC between three stations. The signals of the OSC

and the service signals are independent of each other. The supervisory signals are not amplified.

They are terminated and regenerated at a station.

The following takes the communication between the optical terminal multiplexer (OTM) and

the optical line amplifier (OLA) for example to describe the communication process of the OSC.

Figure 5-49 Signal flow of the OSC between three stations in chain networking

O

O

T

OM

OA

OA

OA

OD

T

U

U

F

F

F

F

SC1

I

I

I

I

SC2

SC1

U

U

U

U

O

O

T

OD

OA

OA

OA

OM

T

U

U

OTM1

OLA

OTM2

In the eastward direction, the HSC1/SC1 at OTM1 receives the overhead data frames from the

SCC. Then, the optical transmit module performs E/O conversion to the frames before the

supervisory data frames is modulated to the OSC wavelength (1510 nm). The multiplexer of the

FIU multiplexes the wavelength of the OSC with the service signals and sends them to the optical

regeneration station OLA.

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The demultiplexer of the FIU at the OLA station demultiplexes the signals into service signals

and OSC signals. The service signals are transmitted to the east after they are regenerated and

amplified by the OAU.

The west optical receive module of the SC2 at the OLA performs O/E conversion to the OSC

signals. The supervisory data frames are recovered and processed before they are sent to the

SCC for data exchange. The east optical transmit module of the SC2 performs E/O conversion

for the processed supervisory signals. The OSC signals and the service signals are multiplexed

by the FIU and sent to the line for transmission.

The demultiplexer of the FIU at the OTM2 station demultiplexes the signals into service signals

and OSC signals. The west optical receive module of the HSC1/SC1 performs O/E conversion

to the OSC signals. The supervisory data frames are recovered and processed before they are

sent to the SCC for data exchange.

In the westward direction, the SCC performs the same process to transmit the required data.

Channel Types

Chan

Description

Bandwidth

Applicable Board

nel

Type

D1-

When receiving

12 x 64 kbit/s

DAS1/HSC1/SC1/SC2/

D3,

supervision information

ST2

D4-

from the SCC board, the

D12

OSC board encapsulates

the information into E1

frames defined in ITU-T

G.703 for further

transmission.

OSC_

OSC_18 is a newly

18 x 64 kbit/s

TN12SC1/TN12SC2

18

developed DCN channel

to improve the OSC

communication capacity.

FE_D

FE electrical ports are

10.24 Mbit/s (shared by

ST2/DAS1a

CN

used to transmit DCN

the OSC and ASON

information.

channels, each assigned

about 5 Mbit/s bandwidth)

a: The WSC port on the board is used to transmit DCN information.

5.11.1.2 Electrical Supervisory Channel Administration

The electrical supervisory channel (ESC) deletes the insertion loss of the FIU. This lowers the

cost and power budget of optical channels.

Functions of the ESC

In the OptiX OSN 8800 system, the monitoring and management information of each station

can be transmitted and communicated through the ESC. The OTU board, tributary board, and

line board realize the ESC transmission by using the DCC bytes or the associated GCC0/1/2

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bytes compliant with ITU-T G.709. The external IP management information can be sent to the

system through the 10 Tbit/s or 100 Tbit/s Ethernet port and then carried by the ESC.

The OptiX OSN 8800 uses the GCC0 or GCC1+GCC2 bytes to achieve the ESC communication.

In this case, the bandwidth varies with the line rate, which is the rate of the OTU.

Working Mode of the ESC

Figure 5-50 shows the signal flow of the ESC for two stations. As shown in the figure, all the

OTUs that support data communication network (DCN) communication at the transmit end

receive the DCN data from the SCC and then send the DCN data to the opposite station. At the

receive end, the SCC selects the DCN data automatically from one route according to the actual

situation. If the route is abnormal, the SCC automatically receives the DCN data from another

route.

The following uses the communication between two OTM stations as an example to describe

the communication of the ESC.

Figure 5-50 ESC signal flow in the chain networking

O

O

T

T

U

U

OA

OA

OM

OM

O

O

S

T

F

F

T

S

U

U

C

I

I

C

C

O

U

U

O

C

T

T

U

U

OD

OA

OA

OD

O

O

T

T

U

U

OTM1

OTM2

In the east, the SCC at OTM1 inserts the supervisory information into the DCN channel in the

overhead serial port according to a specific protocol such as the High-level Data Link Control

(HDLC) protocol. Then the supervisory information is sent to the OTN overhead processing

unit of the OTU through the 2M overhead serial port between the SCC and the OTU. The OTN

overhead is then sent to the line side.

The OTU at OTM2 extracts the overhead from the line side and sends the overhead to the OTN

overhead processing unit through the overhead serial port. The overhead is finally sent to the

SCC.

In the east, the SCC performs the reverse process.

5.11.2 Huawei DCN Solution

Huawei OptiX transmission equipment provides multiple DCN solutions, which will fit various

networks.

DCN Classification by NMS Access Mode

l Indirect access to the NMS: A non-gateway NE accesses the NMS through a gateway NE.

l Direct access to the NMS: An NE accesses the NMS as a gateway NE.

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DCN Classification by Protocol

l HWECC Solution: When the networking is comprised of only the OptiX transmission

equipment, the HWECC solution is preferred. In this solution, NEs transmit the data that

supports the HWECC protocol through DCCs. The solution features easy configuration

and convenient application. As the HWECC protocol is a proprietary protocol, the

management problems cannot be solved when the networking is comprised of both the

OptiX equipment and the third-party equipment.

l IP over DCC Solution: When the networking is comprised of both the OptiX transmission

equipment and the third-party equipment that supports the IP over DCC function, the IP

over DCC solution is preferred. The IP over DCC solution can also be applied when the

networking is comprised of only the OptiX transmission equipment. In the IP over DCC

solution, NEs transmit the data that supports the TCP/IP protocol through DCCs. As the

TCP/IP protocol is a standard protocol, the management problems are solved when the

networking is comprised of both the OptiX equipment and the third-party equipment. The

configuration of the IP over DCC solution is more complicated than that of the HWECC

solution.

l OSI over DCC Solution: When the networking is comprised of both the OptiX transmission

equipment and the third-party equipment that supports the OSI over DCC function, the OSI

over DCC solution is preferred. In the OSI over DCC solution, NEs transmit the data that

supports the OSI protocol through DCCs. As the OSI protocol is a standard protocol, the

management problems are solved when the networking is comprised of both the OptiX

equipment and the third-party equipment. The configuration of the OSI over DCC solution,

however, is more complicated than the configurations of the HWECC solution and the IP

over DCC solution.

DCN Classification by Physical Resource

l Inband port: A DCN is built on service channels provided by equipment under management.

l Outband port: An outband port is a port (usually an Ethernet port) used for data transmission

between NEs on an ASON network. Without using a service path, data transmission can

be achieved by connecting this port to data communication equipment such as an Ethernet

switch or router.

l NMS port: An NMS port refers to the management network port on an NE.

l Transparent transmission: A transparent channel is provided on OTN equipment so that it

does not detect the intermediate network or link.

Table 5-24 lists details on the preceding DCN classifications.

Table 5-24 DCN solutions

Protocol

Indirect

Direct

Inband

Outband

NMS Port

Classificati

NMS

NMS

Port

Port

on

Access

Access

HWECC

Supported

Not

Supporteda

Supported

Supporteda

solution

supported

IP over DCC

Supported

Supported

Supported

Supported

Supported

solution

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Protocol

Indirect

Direct

Inband

Outband

NMS Port

Classificati

NMS

NMS

Port

Port

on

Access

Access

OSI over

Supported

Supported

Not

Supported

Supported

DCC

supported

solution

l a: POS ports are not supported.

l b: Extended ECC is supported.

5.11.2.1 DCN Solution Classification by NMS Access Mode

Indirect NMS Access

In this mode, the NMS sends data to gateway NEs by running the IP or OSI protocol. When

receiving the data, the gateway NEs query the core route table at the application layer by NE ID

and then forward the data to NEs accordingly. Gateway NEs and non-gateway NEs can run the

HWECC, IP, or OSI protocol between themselves.

Direct NMS Access

In this mode, all forwarding NEs on the NMS access path query the IP route table or OSI route

table at the network layer by NE IP address or NSAP address and then forward data from the

NMS accordingly. This mode requires that the NMS and NEs are reachable to each other at the

network layer. That is, a ping test on the NE that is initiated on the NMS is successful.

NOTE

IP and OSI are applicable to the scenarios where Huawei WDM/OTN equipment is interconnected with third-

party equipment.

5.11.2.2 DCN Solution Classification by Protocol

HWECC Protocol

ITU-T G.784 defines the architecture of the ECC protocol stack based on the OSI seven-layer

reference model. The HWECC protocol stack is based on the ECC protocol stack.

The HWECC protocol consists of four layers: physical layer (DCC), media access layer, network

layer, and transmission layer. See Figure 5-51.

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Figure 5-51 Architecture of the HWECC protocol stack

Application layer

Presentation layer

Session layer

Transport layer

Transport layer

Network layer

Network layer

Media access

Data link layer

layer

Physical layer

Physical layer

HW ECC

OSI model

protocol stack

l

Physical layer

The main function of the physical layer is to control physical channels. The physical layer

performs the following functions:

- Receives and sends data over the physical channels, including receiving data from

physical channels and transferring the data to the upper layer.

- Receives the data frames transferred from the upper layer and sends them to physical

channels.

The channels at the physical layer include DCC channels and extended ECC channels. The

physical layer can process the data frame with a maximum of 1024 bytes.

l

Media access layer

The media access layer is also called the medium access control (MAC) layer. The main

function of the MAC layer is to activate or close physical DCCs between the physical layer

and the network layer. The MAC layer shields the diversity of the physical networks and

provides the uniform service upwards (point-to-point physical channel). The MAC layer

performs the following functions:

- Establishes and maintains the MAC connection between adjacent NEs.

When there is a reachable physical channel between two adjacent NEs, the MAC layer

establishes a MAC connection between the NEs. Each MAC connection includes the

address of the opposite NE, the ID of the physical channel, the connection timer, and

other information.

- Provides the data communication service.

The MAC layer receives the data frame transferred from the physical layer. If the

destination address is the local station, the MAC layer transfers the data frame to the

network layer. Otherwise, the MAC layer discards the data frame.

The MAC layer sends the data frame from the network layer. If the destination address

of the data frame has a MAC connection, the MAC layer sends the data frame to the

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