Huawei MD75 SSN1MD75 multi-protocol 32-channels E1 interface processing board Details and Price

OSN 3500 is a new-generation optical transmission system developed by Huawei. It adopts a unified switching architecture and can function as an MPLS/MPLS-TP-based packet device or a TDM device. When working with other devices of Huawei, OSN 3500 supports various networking modes, including the pure packet mode, hybrid networking (packet + TDM) mode, and pure TDM mode, achieving optimal processing for packet services and traditional SDH services. Thus, OSN 3500 efficiently transmits voice and data services over the same platform.

Version Description

The MD75 is available in one functional version, namely, N1.

Version Mapping

Board	Start Version
N1MD75	V200R011C00

Board Updates

This section describes the hardware updates in V200R013C30 and later versions as well as the reasons for the updates. Any product versions that are not listed in the document means that they have no hardware updates.

Application

The MD75 directly receives E1 services from the TDM domain, transmits the E1 services on the packet ring, and directly separates the E1 services from other services on the BSC side. In this manner, the smooth evolution from the TDM domain to the packet domain is implemented.

Figure 1 shows the application of the MD75. The MD75 works with the PEG8 to transmit E1 services on the packet ring.

Figure 1 Networking and application of the MD75

Functions and Features

The MD75 receives and transmits 32xE1 signals and works with the PEG8 to process E1 CES and ATM/IMA services.

Table 1 provides the functions and features of the MD75.

Table 1 Functions and features of the MD75

Function and Feature	MD75
Basic functions	Transmits and receives 32xE1 signals, and works with the PEG8 to process E1 CES and ATM/IMA services.
Interface types	Supports 75-ohm E1 electrical interface. The electrical interface uses the DB44 connector.
Interface characteristics	Loopback types of the port	Inloop Outloop Non-loopback
	Auto disabling of port loopback	Supported
CES	Number of CES services	32
	Emulation mode	CESoPSN, SAToP
	Jitter compensation buffering time of CES services	The jitter compensation buffering time of CES services can be set to a value in the range of 0.375 ms to 16 ms with a step of 0.125 ms.
	Packet loading time of CES packets	The packet loading time of CES services can be set to a value in the range of 0.125 ms to 5 ms with a step of 0.125 ms. NOTE: The packet loading time needs to be set to the same value for the NEs at both ends. The jitter compensation buffering time needs to be more than at least two times of the packet loading time.
ATM/IMA	Number of IMA groups	32
	Maximum number of E1 links in each IMA group	16
	Number of V-UNI ports	512
	Number of V-NNI ports	128
	Cell concatenation	Type: Concatenation Non-concatenation
		Quantity: 31
	ATM OAM	Type: CC LB RDI AIS
		Quantity: 512
	Service categories	CBR, UBR, UBR+, rt-VBR, nrt-VBR
	ATM QoS	Supported
Clock function	Recovers four CES ACR clocks. Clocks that are recovered from services over ports 1 and 9 can be added to the clock priority list. NOTE: Clock recovery over ports 1 to 16 is independent of clock recovery over ports 17 to 32. That is, clocks that are recovered from services over ports 1 to 16 can be transmitted out of ports 1 to 16 and clocks that are recovered from services over ports 17 to 32 can be transmitted out of ports 17 to 32.
Clock mode	Line Clock Mode and Null.
Line code of E1 link	HDB3 code
Frame format of E1 link	Unframed format, double-framed format, or E1 CRC-4 multiframe format (default value)
Loopback mode	Inloop, outloop, or non-loopback (default value)
Maintenance features	Supports the query of the board manufacturer information. Supports the in-service loading of the FPGA. Supports the upgrade of the board software without affecting services. Supports the PRBS function. For details, see Availability. Hot board swapping.

Working Principle and Signal Flow

The MD75 consists of the tributary processing module, service processing module, management module, clock module, and power supply module.

Figure 1 shows the functional block diagram of the MD75.

Figure 1 Functional block diagram of the MD75 

Receive Direction

The tributary processing module receives E1 signals, and performs the functions of impedance matching, signal equalization, level conversion, clock recovery, de-jitter, and decoding. After the tributary processing module processes the E1 signals, the signals are sent to the service processing module for framing, PWE3 encapsulation and mapping, and PW scheduling. Then, the signals are sent to the PEG8 through the backplane interface module.

Transmit Direction

The cross-connect unit receives packets from the backplane interface module, and sends the packets to the service processing module. The service processing module decapsulates the packets, buffers the data in queues, schedules the queues based on service types, and then processes and converts the data. The converted data is sent to the tributary processing module. The tributary processing module performs the functions of coding, dejitter, pulse shaping, and line drive, and then sends the services to E1 interfaces.

Tributary Processing Module

The tributary processing module consists of 32 independent receive channels and transmit channels.

• The receive channels implement the functions of impedance matching, signal equalization, level conversion, clock recovery, de-jitter, and decoding.
• The transmit channels implement the functions of coding, dejitter, pulse shaping, and line drive.

Service Processing Module

The service processing module performs the following functions:

• In the receive direction, the service processing module obtains the PW information of each E1 service, performs PWE3 encapsulation and PW scheduling, and then sends the signals to the PEG8 through the backplane interface.
• In the transmit direction, the service processing module receives the services from the PEG8, identifies different service types, and performs PWE3 decapsulation and service scheduling.

Management Module

The management module manages and controls the modules on the MD75.

Clock Module

Provides the clock signal for each module of the MD75.

Power Module

The power module converts the accessed DC voltage into the DC voltages that the modules of the board require.

Front Panel

The front panel of the MD75 has interfaces and a bar code.

Diagram of the Front Panel

Figure 1 shows the appearance of the front panel of the MD75.

Figure 1 Front panel of the MD75

Interfaces

The front panel of the MD75 has four DB44 interfaces. Table 1 describes the types and usage of the interfaces of the MD75.

Table 1 Interfaces of the MD75

Interface	Type of Interface	Usage
1-8	DB44	Receives E1 signals from the 1st channel to the 8th channel.
9-16	DB44	Receives E1 signals from the 9th channel to the 16th channel.
17-24	DB44	Receives E1 signals from the 17th channel to the 24th channel.
25-32	DB44	Receives E1 signals from the 25th channel to the 32nd channel.

Table 2 lists the pins of the DB44 interface.

Table 2 Pin description of the DB44 interfaces on the MD75

Front View	Pin	Usage	Pin	Usage
	38	R1 to receive the first channel of signals	34	R5 to receive the fifth channel of signals
	23		19
	37	R2 to receive the second channel of signals	33	R6 to receive the sixth channel of signals
	22		18
	36	R3 to receive the third channel of signals	32	R7 to receive the seventh channel of signals
	21		17
	35	R4 to receive the fourth channel of signals	31	R8 to receive the eighth channel of signals
	20		16
	15	T1 to transmit the first channel of signals	11	T5 to transmit the fifth channel of signals
	30		26
	14	T2 to transmit the second channel of signals	10	T6 to transmit the sixth channel of signals
	29		25
	13	T3 to transmit the third channel of signals	9	T7 to transmit the seventh channel of signals
	28		24
	12	T4 to transmit the fourth channel of signals	8	T8 to transmit the eighth channel of signals
	27		7

Jumpers and DIP Switches

The MD75 does not have any jumpers or DIP switches that are used for board settings.

Valid Slots

The MD75 must be installed in a valid slot in the subrack. Otherwise, the MD75 fails to work normally.

The MD75 can be installed in any slot of slots 19-26 and slots 29-36.

The MD75 needs to be used with the PEG8. Table 1 lists the slots valid for the PEG8 and the corresponding slots for the MD75

Technical Specifications of the MD75

The technical specifications of the MD75 include the specifications of electrical interfaces, mechanical specifications, and power consumption.

Specifications of Interfaces

Table 1 Specifications of the ports

Port type	Description
E1 electrical interfaces	75 ohm E1 electrical interfaces

Mechanical Specifications

The mechanical specifications of the MD75 are as follows:

• Dimensions (mm): 22.0 (W) x 125.2 (D) x 261.4 (H)
• Weight: 0.5 kg

Power Consumption

The maximum power consumption of the MD75 at room temperature (25°C) is 12 W.

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