Private Line Synchronous Service Transport (SST)

The Next Step in the Evolution of Voice, Data and Video Transport

Ensure high-capacity transport for your changing business needs with SST.

Are your voice, data, and video transport needs outgrowing the capacity of your existing DS-1 or DS-3 lines? Synchronous Service Transport (SST) is a two-point broadband, shared Private Line solution that provides you with a reliable high-capacity connection for the transfer of large volumes of traffic. SST can help grow your business by offering economies of scale, scalability and interoperability.


Consolidates Your Lower-Speed Services

Grows With Your Business to Meet Your Future Needs

Offers 24/7 Network Monitoring and Repair Availability

Eliminates Valuable Network Downtime

Provides Enhanced Network Survivability via Optional SHARP Capabilities

Works with PRI and DDS Data and Voice Trunks, FRS and ATM Packet Services and DWDM Technologies


Interoperability with Most Data Format System Types:

  • Interoperability across equipment vendors 
  • Primary rate interface (PRI) and digital data services (DDS) data and voice trunks 
  • Frame relay service (FRS) and asynchronous transfer mode (ATM) packet services 
  • Newer dense wavelength division multiplexing (DWDM) technologies 

Speeds of 155.52 Mbps for OC-3, 622.08 Mbps for OC-12, 1.2 Gbps for OC-24, 2.49 Gbps for OC-48 and 9.95 Gbps for OC-192.

Channelized and Concatenated Service Availability 

Superior Quality of Service:

  • Throughput equals purchased bandwidth (no congestion) 
  • Visibility to data channels 
  • Advanced monitoring/alarming and performance characteristics 
  • SLAs for service availability, mean time to repair (MTTR) and customer notification 
  • Optional Self-Healing Alternate Route Protection [link to ] (SHARP) availability allows separation of working and protect fiber 
  • Electronic redundancy maximizes service availability and survivability 

SONET Technology Offering High Reliability and Survivability.

24/7 CenturyLink Monitoring

How It Works

SST is a point-to-point service that connects two customer or wire center locations. You can also tie together more locations by cross-connecting SST systems or connecting with other services. Should your network sustain a fiber cut, SST’s four-fiber configuration makes it possible for your network to remain functional. The service allows multiple circuit types, such as DS-1, DS-3, STS-1, OC-3, OC-3c (concatenated), OC-12, OC-12c, OC-48, OC-48c, 10 Mb Ethernet, 100 Mb Ethernet and 1 Gigabit Ethernet, to ride the SST separately or in combination, meeting your unique volume-transport needs. SONET technology ensures your network has the highest level of survivability available today. 

Network Maps

The CenturyLink network covers the entire continental United States and has one of the largest fiber footprints. Internationally, we provide coverage to hundreds of destinations.

More Services and Solutions for You

Metro Ethernet

Boost network application performance and increase network flexibility.

Ethernet over Self-Healing Network Services (SHNS)

Business continuation, disaster recovery, and survivability through a failure-resistant telecommunications network.

Contact an Expert

Chat with Us

Chat with one of our online sales consultants:

Call Us

Call us for further assistance:


Email Us

Please provide the following contact information and we will follow up with you soon.
* - Denotes a required field.

Get Connected. See What's Next for Business.