Introduction to transceivers

In switch or router, the first component customers facing is optical transceiver, which is used to connected optical fibre to PHY or EDCs inside switch/router. Transceiver is the device to convert optical signal to electrical signal, which could be processed by modern switch/router. The following is one list of optical transceivers commonly used in networking industry.

1. GBIC(10M/100M/1000M)
2. SFP/mini-GBIC(10M/100M/1000M)
3. XENPAK(10G)
4. X2(10G)
5. XFP(10G)
6. SFP+(10G)
7. QSFP(40G)
8. CXP(100G)
9. CFP(100G)

Transceivers evolve  with smaller size and higher speed.  Most transceivers have the following features.

• have EEPROM accessible via I2C or MDIO 
• hot-pluggable
• used with Ethernet or fibre channel. 
• support bi-directional communications, while others only support one direction -- either up link or down link only. 
• only support 1 speed, while others maybe  support multiple speeds.
• no PHY inside, while some have PHY embedded.