JetNet 3908G-M12 Industrial Full Gigabit Un-Managed Booster PoE Switch

The JetNet 3908G-M12 is a new generation Powerover-Ethernet Switch with rugged M12 connectors. It is designed for IP Surveillance in harsh environments such as Train, MRT, and LRV systems and is equipped with 8 PoE/PSE Gigabit interface. The PSE system enables 30W high power PoE function and is compliance with IEEE 802.3af/at standard. The switch system adapts to vehicle/railway electrical power system and supports several types of input voltage rating to correspond with different train electrical power systems. With multi-backup features, the JetNet 3908G-M12 is capable to construct IP Surveillance network on the train, ensure passenger's safety and improve train network reliability

JetNet 3908G-M12 Industrial Full Gigabit Un-Managed Booster PoE Switch

  • 8 Gigabit/PSE M12 X-code, M12-A Power

  • Power feeding 15.4W/30W, compliance with IEEE 802.3af/at

  • Power System design up to 180W PoE budget and compliance with safety requirement

  • Rugged M12 Ethernet, power  connectors for vibration and shock application

  • IEEE 802.1p Class of Service (CoS) for packet forwarding precedence

  • 10K bytes Jumbo Frame for large file transmission

  • Broadcast storm packet filtering

  • Embedded DC 54V Booster

  • Railway Standards: EN50155, EN50121-3-2, EN50121-4

  • Traffic Standard: E-mark E13

  • -40~75℃ operating temperature



IEEE 802.3u 10Base-T Ethernet
IEEE 802.3u 100Base-TX Fast Ethernet
IEEE 802.3ab 1000Base-TX Gigabit Ethernet
IEEE 802.3af Power over Ethernet
IEEE 802.3at High Power PoE with 2-Event classification
IEEE 802.3x Flow control and back-pressure

Network Performance

Switch Technology

Store and Forward technology with 16Gbps non-blocking

System Throughput

23.8Mega packets per second, 64Bytes packet length

Transfer packet size

64Bytes ~1518Bytes

MAC Address

16K MAC address table

Packet Buffer

2 Mega bits shared packet buffer

Broadcast storm

Default enabled
Traffic threshold:
25M bps@1000Mbps;
10M bps@100Mbps;
1M bps@10 Mbps

Jumbo frame

Up to 10K Bytes

Transfer performance

14,880 pps @10Mbps
148,800 pps @100Mbps
1,488,100 pps @1000Mbps

Class of Service

Default Enabled
Compliance with IEEE802.1p class of service with Tag Based Priority rule. Each switch port
provides 4 priority queues as following – 8 (Higher) : 4(High) : 2(Low) :1(Lower) scheduling.
The Tag Priority ID as following: Highest (6,7), High (4,5), Low (0,3), Lowest (1,2)

Power over Ethernet

Power over Ethernet

IEEE 802.3af/at, End-Span wiring architecture

PoE operating mode

Auto Mode: IEEE 802.3af/at behaviors with IEEE 802.3at 2-Event for high power IEEE 802.3at
2-event PD device

PoE forwarding

M12 X-Code (Port 1): V+(1,2), V- (3,4)

Power forwarding

IEEE 802.3af:15.4 W, IEEE802.3at:30W

PoE System Power

Power Budget Reserve by PD declaration. The power budget control system will reserve power
for connected PD device. Once the latest PD device claimed power over the system surplus
power budget, the highest port of PoE will not be active due to port order mechanism.
System Power Budget: up to 180Watts at DC 24V/ 60 Watts at DC 12V


Enclosure Port

1000 Base-T/Gigabit Ethernet (Port #1): 8 x M12-X Code 8-pin Female
M12-X (Conductor #): (#1) 0P(D1+)/PoE V+, (#2) 0N(D1-)/PoE V+, (#3)1P(D2+)/PoE V-
, (#4)1N(D2-)/PoE V-, (#5)3P(D4+) (#6)3N(D4-), (#7) 2N (D3-), (#8) 2P (D3+)
Power: M12 A-Code 5-pin Male

LED Indicators

Port 1~8: Link (Green on)/Activity (Green Blinking)
PoE Detection (Amber Blinking)/ PoE power forwarding (IEEE 802.3af/at-Amber on)
Power: System Power Ready (Green on), Ignition function Activity ( Green Blinking)

Power Requirement

System Power

Input voltage: DC 12V or DC 24V, variation range DC 9- 36 V

Power consumption

6 Watts @ DC 24V without PD loading
Up to 180 Watts @ DC 24V max.

Power Ignition Management

The count-down timer supports 4 scenarios which can be configured by Rotary-switch. The
detail shows in user manual.




Wall Mounting

Enclosure Material

Steel Metal with textured paint

Ingress Protection

IP-41 (IP54 available by request)

Dimension (mm)

116 mm (H) x 140 mm (W) x 58 mm (D) (without wall mount clip)

Weight (Kg)



Operating Environment

-40°C~75°C (120 Watts PoE/PD Loading), 0~90%, Non-condensing

Storage Environment

-40°C~85°C, 0~90% Non-Condesing


AC 1KV for ports-power, power-case


Railway Standard

EN50155, EN 50121-4, EN50121-3-2


E-mark E13 10R-05 14802


EMI: EN50121-3-2, FCC Class A, IEC/EN61000-6-4
EMS:EN50121-3-2/EN50121-1, IEC/EN61000-6-2
IEC/EN61000-4-2, IEC/EN61000-4-3, IEC/EN61000-4-4, IEC/EN61000-4-5,
IEC/EN61000-4-6, IEC/EN61000-4-8, IEC/EN61000-4-9


IEC 61373

Free Fall

IEC 60068-2-32 with package Note-1

MTBF (hrs)



5 Years

JetNet 3908G-M12

Industrial Un-Managed Booster PoE Switch 8 PoE/PSE Gigabit Port