S5720-28X-LI-24S-DC

Version Mapping

Table 1 lists the mapping between the S5720-28X-LI-24S-DC chassis and software versions.

**Table 1** Version mapping
Series	Model	Software Version
S5720-LI	S5720-28X-LI-24S-DC	V200R010C00 and later versions

Appearance and Structure

Figure 1 S5720-28X-LI-24S-DC appearance

1	Sixteen 100/1000BASE-X ports Applicable modules: FE optical module GE optical module GE-CWDM optical module GE-CWDM optical module (used only in the OADM scenario and supported in V200R012C00 and later versions) GE-DWDM optical module GE copper module (works at 10 Mbit/s, 100 Mbit/s, or 1000 Mbit/s)	2	Eight combo ports (10/100/1000BASE-T + 100/1000BASE-X) Modules applicable to combo optical ports: FE optical module GE optical module GE-CWDM optical module GE-CWDM optical module (used only in the OADM scenario and supported in V200R012C00 and later versions) GE-DWDM optical module
3	Four 10GE SFP+ ports Applicable modules and cables: GE optical module GE-CWDM optical module GE-DWDM optical module GE copper module (only 1000 Mbit/s supported) 10GE SFP+ optical module (OSXD22N00 not supported) 10GE-CWDM optical module 10GE-DWDM optical module 1 m, 3 m, 5 m, and 10 m SFP+ high-speed copper cables 3 m and 10 m AOC cables 0.5 m and 1.5 m SFP+ dedicated stack copper cables (used for zero-configuration stacking, supported in V200R011C10 and later versions) H87MMA5671A2 GPON optical module (applicable in V200R012C00 and later versions) NOTE: If a port uses a GPON optical module, other 10GE SFP+ optical ports cannot be used.	4	One PNP button NOTICE: Applicable in V200R012C00 and later versions: To restore the factory settings and reset the switch, hold down the button for at least 6 seconds. To reset the switch, press the button. Resetting the switch will cause service interruption. Exercise caution when you press the PNP button.
5	One console port	6	One USB port
7	DC power terminal NOTE: It is used together with a DC Power Cable.	8	Ground screw NOTE: It is used with a ground cable.
9	RPS socket NOTE: It is used with an RPS cable, which is not hot swappable.	-	-

Port Description

100/1000BASE-X port

A 100/1000BASE-X port can send and receive data at 100 Mbit/s or 1000 Mbit/s. Table 2 describes the attributes of a 100/1000BASE-X port.

**Table 2** Attributes of a 100/1000BASE-X port
Attribute	Description
Connector type	LC/PC
Optical interface attributes	Depend on the optical module used
Standards compliance	IEEE802.3z
Working mode	100/1000 Mbit/s auto-sensing

Combo port

A combo port consists of an optical Ethernet port and an electrical Ethernet port on the panel. Each combo port matches only one internal forwarding port. The electrical and optical ports of a combo port are multiplexed, and only one of them can work at a time. When one of the Ethernet ports is working, the other port is shut down.

By default, a combo port works in auto mode, in which the port type is determined as follows:

If the optical port has no optical module installed and the electrical port has no Ethernet cable connected, the port type depends on which port is connected first. If the electrical port is connected by an Ethernet cable first, the electrical port is used for data switching. If the optical port has an optical module installed first, the optical port is used for data switching.
If the electrical port has an Ethernet cable connected and is in Up state, the electrical port is still used for data switching when the optical port has an optical module installed.
If the optical port, no matter in Up or Down state, has an optical module installed, the optical port is still used for data switching when the electrical port has an Ethernet cable connected.
If the optical port has an optical module installed and the electrical port has an Ethernet cable connected, the optical port is used for data switching after the switch restarts.

You can configure a combo port as an electrical or optical port using the combo-port command.

10GE SFP+ port

A 10GE SFP+ Ethernet optical port supports auto-sensing to 1000 Mbit/s. It sends and receives service data at 1000 Mbit/s or 10 Gbit/s. Table 3 describes the attributes of a 10GE SFP+ Ethernet optical port.

**Table 3** Attributes of a 10GE SFP+ port
Attribute	Description
Connector type	LC/PC
Optical port attributes	Depend on the optical module used
Standards compliance	IEEE802.3ae
Working mode	GE/10GE auto-sensing

Console port

The console port is connected to a console for on-site configuration. The port must use a console cable. The console port is used when a switch is powered on for the first time. For details about the attributes of a console port, see Table 4.

**Table 4** Attributes of a console port
Attribute	Description
Connector type	RJ45
Standards compliance	RS-232
Working mode	Duplex Universal Asynchronous Receiver/Transmitter (UART)
Baud rate	9600 bit/s, 19200 bit/s, 38400 bit/s, 57600 bit/s, or 115200 bit/s Default value: 9600 bit/s

USB port

The USB port can have a USB flash drive connected to upgrade the switch, or transfer configuration files or other files. The USB port can only connect to a USB flash drive that complies with USB 2.0.

USB flash drives from different vendors differ in model compatibility and drivers. If a USB flash drive cannot be used, try to replace it with another one from a mainstream vendor. Switches support a maximum of 128 GB USB flash drives.

Indicator Description

The S5720-28X-LI-24S-DC has the same types of indicators as the S5720-28X-LI-24S-AC. For details, see Indicator Description.

Power Supply Configuration

The S5720-28X-LI-24S-DC has a built-in power module and does not support pluggable power modules. It can connect to an RPS1800 power supply for power redundancy.

Figure 2 shows the power supply mode of a single DC power module. The built-in DC power module (PWR) receives DC power from an external power source and provides a 12 V output to the chassis.

Figure 2 Power supply by a single DC power module

NEG: negative wire

RTN: positive wire

GND: 12 V reference ground

Heat Dissipation

The S5720-28X-LI-24S-DC has a built-in fan for forced air cooling. Air flows in from the left side and front panel, and exhausts from the right side.

This figure only shows the airflow direction and does not depict the actual device.

Technical Specifications

Table 5 lists technical specifications of the S5720-28X-LI-24S-DC.

**Table 5** Technical specifications
Item	Description
Memory (RAM)	512 MB
Flash	512 MB in total. To view the available flash memory size, run the display version command.
Mean time between failures (MTBF)	41 years
Mean time to repair (MTTR)	2 hours
Availability	> 0.99999
Service port surge protection	Common mode: ±7 kV
Power supply surge protection	±1 kV in differential mode, ±2 kV in common mode
Dimensions (H x W x D)	43.6 mm x 442.0 mm x 220.0 mm (1.72 in. x 17.4 in. x 8.7 in.)
Weight (with packaging)	4.1 kg (9.04 lb)
Stack ports	GE SFP optical ports except combo ports and 10GE SFP+ optical ports
RTC	Not supported
RPS	Supported
PoE	Not supported
Rated voltage range	-48 V DC to -60 V DC
Maximum voltage range	-36 V DC to -72 V DC
Maximum power consumption (100% throughput, full speed of fans)	42.7 W
Typical power consumption (30% of traffic load) Tested according to ATIS standard EEE enabled No PoE power consumption	30.3 W
Operating temperature	0°C to 45°C (32°F to 113°F) at an altitude of 0-1800 m (0-5906 ft.) NOTE: When the altitude is 1800-5000 m (5906-16404 ft.), the highest operating temperature reduces by 1°C (1.8°F) every time the altitude increases by 220 m (722 ft.).
Short-term operating temperature	-5°C to +55°C (23°F to 131°F) at an altitude of 0-1800 m (0-5906 ft.) NOTE: When the altitude is 1800-5000 m (5906-16404 ft.), the highest operating temperature reduces by 1°C (1.8°F) every time the altitude increases by 220 m (722 ft.). The equipment can operate beyond the normal operating temperature range for a short-term period, but the following conditions must be met: The equipment operates at a temperature of over 45°C (113°F) consecutively for at most 96 hours in one year. The equipment operates at a temperature of over 45°C (113°F) for a total of no more than 360 hours in one year. The equipment operates at a temperature of over 45°C (113°F) for no more in 15 times in one year. The equipment may be damaged or experience unexpected exceptions if any of the preceding limits is exceeded. The equipment cannot start when the temperature is lower than 0°C (32°F). The maximum distance of optical modules used in these conditions cannot exceed 10 km.
Storage temperature	-40°C to +70°C (-40°F to +158°F)
Noise under normal temperature (27°C, sound power)	< 43 dB(A)
Relative humidity	5% to 95%, noncondensing
Operating altitude	0-5000 m (0-16404 ft.)
Certification	EMC certification Safety certification Manufacturing certification
Part number	98010631