Hard Pipe — The Best Choice for Private Circuit of Key Clients

Posted on Jul 27, 2023 by

The market for hard pipe private lines based on traditional SDH/MSTP/OTN/WDM technology is still growing, but with the rapid development of packet technology and network, some operators and major customers are gradually considering the feasibility of packet private lines. Connection-oriented and service isolation are the basic requirements of a private circuit of key clients. Performance index and efficient operation and maintenance capability of private wire networks are also important factors for key customers to make choices. Compared with the packet dedicated line, the hard pipe private circuit still has irreplaceable advantages and is one of the best choices for key customer lines.

Core Requirements of Private Circuit of Key Clients

All over the world, governments, enterprises, organizations and individuals have increasingly high requirements for information security. Symentac, a well-known security firm, estimates that the cost of cybercrime around the world could go as high as $388 billion a year. For the private circuit of key clients, the service provided must have sufficient security and achieve the special use of the private line. From a technical point of view, the special line business must be pipelined, which means connection orientation, and different users of the private line business isolated from each other.


What key customers pay most attention to about private circuit service is reflected in SLA. The private circuit service SLA provided by all operators mainly includes service quality and operation and maintenance capabilities, and the typical commitment values are as follows:

 Category  SLA Indicator  Typical Commitment Value
Service Quality  Availability  99.95%~100%
 Bit Error Rate  10E-09
 Latency  37~55ms
 Jitter  1~5ms
 Packet Loss  0.01%~1%
Operation & Maintenance  Opening Time  Few days
 MTTR  2~4h

The service quality and operation and maintenance capacity of private wire networks using different technologies are quite different, and those with high-quality and efficient operation and maintenance are more likely to get the favor of VIP customers.

Bandwidth Satisfaction

In addition to service SLA, bandwidth satisfaction is also a must for private wire networks. The internal and external business operation mode of key customers in various industries has been further networked, and the popularity of new services such as video communication and telepresence has brought great pressure on the total bandwidth of private wire networks. According to the statistical survey report of the British communication control agency Ofcom, more than 80% of the private bandwidth of a single key customer is still below 100M, so the scheduling capability of small particle services in the private wire network is still a necessity.

To sum up, the private circuit pipeline network of key clients must have high-quality and efficient operation and maintenance capabilities, support larger network bandwidth evolution, and be compatible with small-particle service scheduling.

Advantages of the Hard Pipe over Elastic Pipe

Common private wire network technologies can be further subdivided into hard pipe, elastic pipe and non-pipe.

 Private Line  Internet  Interface/Business Lines  Isolation Based on Connection  Dedicated Bandwidth
Hard pipe  SDH/MSTP  PDH, SDH, Eth  √  √
 OTN/WDM  OTN, Eth, SDH, FC  √  √
Elastic Pipe  ATM/FR  ATM PDH & SDH, FR  √  ×
 IP MPLS  E1(CES), Ch-STM-1,Eth, VPWS, VPLS, IP VPN  √  ×
 MPLS-TP  E1(CES), Ch-STM-1,Eth, VPWS, VPLS  √  ×
Non-Pipe  Eth Switch  Eth  ×  ×
 xDSL/FTTx  Eth  ×  ×
 3G/LT  Eth  ×  ×

Hard pipelines are widely used in long-distance lines, mobile bearers, and high-security dedicated communication control networks (such as power and railway). Elastic pipelines are prominently used in enterprise Internet access, network marketing, ordinary video surveillance and other applications with more burst traffic. They are less used in the private circuit of key clients, mostly in personal Internet access and low-security applications. Compared with the elastic pipe network, the hard pipe network is more in line with the needs of the evolution of the key customer private wire network.

Better Performance of Hard Pipeline

The perfect protection mechanism makes the hard pipeline private circuit the only choice for network equipment in the railway industry. The actual network construction of the railway industry requires redundancy of all components, including interfaces, equipment and control systems. The private lines for different systems must be dedicated, so that various systems in railway operation can avoid mutual influence and ensure safety to the greatest extent. In the current equipment technology, only SDH-based hard pipeline equipment can provide complete device-level and network-level protection, and achieve strict physical isolation between different services with less-than-50ms protection switch time. Generally, the elastic pipeline network based on IP/MPLS, lacking a perfect protection mechanism, can only provide physical isolation, and supports the fast rerouting capability of 200ms, which is difficult to reach 50ms.

For the transmission of video services, hard-pipe lines also have obvious advantages. Compared with elastic pipeline system, hard pipeline can support error switching, and the bit error rate can be arbitrarily set between 10E-3 and 10E-09. The elastic pipeline network does not have error switching. Only when the bit error rate is very high and a large number of packets are lost can the network rerouting or protection switching be triggered. At this time, the Mosaic phenomenon has been quite serious, and the video service experience is very poor.

When the elastic pipeline system is used for high-definition telepresence video services, the latency is less than 50ms, and the packet loss rate is less than 0.5%, while the hard pipeline can naturally meet the requirements of these indicators, and the actual bandwidth demand is smaller than that of the elastic pipeline. For example, for the 3-screen 1080p/60fps telepresence application, the elastic pipeline needs 14.4Mb bandwidth, while the hard pipeline only requires 6xE1, namely 12Mb bandwidth.

Hard pipe private line system generally provides the forward error correction(FEC) of the line interface. The current solution can correct error codes below 10E-3, which can not only improve the transmission distance, but also correct error codes in case of system deterioration. Experiments show that FEC can greatly improve the bearing experience of video and other services in the private line system. Elastic pipe systems generally lack FEC capacity.

More Efficient Operation and Maintenance

In the current market of private circuit of key clients, the service opening time is a key competitive point, and it is obvious that the hard pipeline private network is better. The quick fix of the private wire network can not only reduce the loss of customers, but reduce the operator's compensation loss to customers.

Generally, hard pipe network resources can be visually viewed on the network management, providing end-to-end available resource reports. When services are needed, people only need to click to start services. Elastic pipeline network resource search and service configuration still need to be explored and configured based on experience, which takes a long time and cannot provide end-to-end one-click services.

In terms of network fault location, service overhead is embedded in the signal frame of the hard pipeline network which supports real-time alarm and performance monitoring. Because the network protocol is simple, network devices support alarm suppression, and the network management system supports smart fault location, the fault recovery and location time are generally less than 30 minutes. Locating elastic pipeline network faults takes several hours and requires skilled maintenance personnel.

Better Compatibility and Cost-Effective Bandwidth Expansion

The hard pipe private line network has a long history and strong service provision capability. In addition to the usual PDH/SDH/ETH/FC services, it can also support the sub-rate private line services used by special industries such as 64k/Nx64K, and better technical specifications to meet the needs of PCM applications. In terms of bandwidth expansion, the backbone layer can provide 10T class bandwidth through OTN/WDM technology. FS's enterprise multi-service network isolation solution, based on the hard pipe transmission technology, with the use of MS8100 series products, can achieve large-bandwidth service carrying, and OTN adopts multi-wavelength technology to further improve the transmission capacity and meet the large bandwidth requirements of high-definition video surveillance data transmission.


The global key customer private line market is growing steadily. Hard pipe private line can provide the best business performance, efficient operation and maintenance and the best expansion compatibility, these advantages are difficult to be caught up by the elastic pipeline line in a short time. Therefore, hard pipe private line is still the best technical choice for the key customer private wire network.

You might be interested in

See profile for Sheldon.
Decoding OLT, ONU, ONT, and ODN in PON Network
Mar 14, 2023
See profile for Irving.
What's the Difference? Hub vs Switch vs Router
Dec 17, 2021
See profile for Sheldon.
What Is SFP Port of Gigabit Switch?
Jan 6, 2023
See profile for Migelle.
PoE vs PoE+ vs PoE++ Switch: How to Choose?
May 30, 2024
See profile for Moris.
How Much Do You Know About Power Cord Types?
Sep 29, 2021