- Fiber Optic Transceiver Module
- High Speed Cable
- Fiber Optical Cable
- Fiber Optical Patch Cords
- Splitter CWDM DWDM
- PON Solution
- FTTH Box ODF Closure
- PCI-E Network Card
- Network Cables
- Fiber Optical Adapter
- Fiber Optical Attenuator
- Fiber Media Converter
- PDH Multiplexers
- Protocol Converter
- Digital Video Multiplexer
- Fiber Optical Tools
- Compatible
- Data Center Solutions
- Top 5 features of xPON OLTs ...
- SFP-10G-SR and SFP-10G-LR ...
- Fused Biconic Tapered Splitt...
- What is TDMOIP
- The direct difference betwee...
- Nondispersion-Shifted Fiber(...
- About OM3 fiber
- What is an optical fiber
- The feature of Multi-mode op...
- HBA card
- About HBA
- Fiber closure
- Active Fiber Optic Cable Con...
- What are the types of fiber ...
- Sopto SC and FC Fiber Fast C...
- Outdoor FTTH Cabinet
- CWDM multiplexer
- DWDM multiplexer
- What is the advantages of di...
What's SDH
Synchronous Optical Networking (SONET) and Synchronous Digital Hierarchy (SDH) are standardized protocols that transfer multiple digital bit streams over optical fiber using lasers or highly coherent light from light-emitting diodes (LEDs). At low transmission rates data can also be transferred via an electrical interface. The method was developed to replace the Plesiochronous Digital Hierarchy (PDH) system for transporting large amounts of telephone calls and data traffic over the same fiber without synchronization problems.
SONET and SDH, which are essentially the same, were originally designed to transport circuit mode communications from a variety of different sources, but they were primarily designed to support real-time, uncompressed, circuit-switched voice encoded in PCM format.The primary difficulty in doing this prior to SONET/SDH was that the synchronization sources of these various circuits were different. This meant that each circuit was actually operating at a slightly different rate and with different phase. SONET/SDH allowed for the simultaneous transport of many different circuits of differing origin within a single framing protocol. SONET/SDH is not itself a communications protocol per se, but a transport protocol.
Due to SONET/SDH's essential protocol neutrality and transport-oriented features, SONET/SDH was the obvious choice for transporting the fixed length Asynchronous Transfer Mode (ATM) frames also known as cells. It quickly evolved mapping structures and concatenated payload containers to transport ATM connections. In other words, for ATM (and eventually other protocols such as Ethernet), the internal complex structure previously used to transport circuit-oriented connections was removed and replaced with a large and concatenated frame (such as STS-3c) into which ATM cells, IP packets, or Ethernet frames are placed.
Related: sfp transceiver module