High-Speed Serial Interface (HSSI)
HSSI is High Speed Serial Interface was first developed by Cisco systems and the main purpose was to solve high speed requirement issues. The main application of HSSI is on the Wide Area Networks and it helps to enhance the data flow speed on these networks. It can work on both physical and electrical devices using the DTE and the DCE interfaces.
There are many features that contribute to the characteristics of the HSSI working model.
- On HSSI you can receive signals up to 52 Mbps, which means that the HSSI model can easily handle the T3 requirements or of any WAN models existent today.
- High speed connectivity can easily be provided using the HSSI model on Local Area Networks using the network topologies such as the Token Ring and the Ethernet.
- HSSI can transmit high levels of data and at low noise levels because it uses the ECL or the Emitter Coupled Logic. The ECL technology helps the internet by ensuring the time margins are met and takes care of the data flow efficiency.
- HSSI is built on only male pins which reduced the need for male to male pins connection or female to female pin connections. It uses the hardware’s used by SCSI (Small Computer Systems Interface), however the electrical specifications for the HSSI model is based a more specific patterns.
Allocation of bandwidth on the HSSI model happens using the clock and data signaling process which is a protocol that makes it possible to allocate a certain amount of bandwidth on the network for individual applications on the same network. There will be many applications running on the same network and most of them would need constant bandwidth support like the PBX systems, servers, routers, and the LAN or the WAN.
HSSI manages the bandwidth smartly by identifying the individual need for bandwidth by timing the bandwidth and makes sure that all applications have the right amount of bandwidth at any given point of time. Yet the functionality is so simple using its DCE and the DTE interface.
With a simple DCE available and DTE available signaling process the HSSI manages the circuits efficiently. This method of approach also reduced the dependency on many circuits and the lesser the number of circuits the lesser the number chances of failing are.
As a back up the HSSI also conducts loop back testing to ensure that the networks are functioning properly. The HSSI also has two loop back modes for the DTE and the DCE ports. Though [pioneered by Cisco systems now HSSI has found wide acceptance due to its multi functionality.
Among all the interface technology why is HSSI so popular? Because it comes form the experts of the industry and it was the first one to meet the high speed data connectivity requirements in Wide Area Networks. When you take a closer look at the HSSI technology ware you find hat the pins at the end of the HSSI cable are much smaller than the pins on a regular LAN or WAN cable.
This is one of the main differences between a SCSI model and the HSSI model. IS this making the data performance on HSSI better? Perhaps in a lesser significant way because the HSSI model is making the electrical connections more defined by using smaller pins. However when all the features of HSSI are put together you find that each one is working with the other to make it a successful technology and very rarely do we come across such scenarios.