Indoor Transition Splice

Indoor Transition Splice Architecture

Indoor Transition Splice Architecture

When transitioning fiber and cable from outdoors to indoors, operators require a rugged enclosure optimized for quick re-entry and network expansion. The transition splice occurs in a different location from the optical fiber distribution frames to better manage the fiber and cable. Why is the transition splice important? Because the outdoor cable is not optimized for indoor environments. Indoor cable is flame-rated, so industry standards require this transition within 50 feet of entering a building.

There are three areas the indoor transition splice can occur within the network:

  • Building Entrance Terminals: Indoor or outdoor terminals that provide protection for the point where OSP cable transitions to inside plant cable.
  • Splice Vaults: An underground vault that acts as a demarcation point where the cables transition from outside plant to inside plant before reaching the central office, headend, or MSC building.
  • Equipment Rooms: An above-ground space in a central office, headend, or MSC site that houses electronics where the outside plant cable and transition to inside plant cable can occur. The splice allows equipment to serve the building and surrounding buildings.


Corning’s optical splice enclosure (OSE) portfolio offers varying densities, scalability, and excellent fiber management, with routing guide plates that organize and separate stored fiber and fiber entering splice trays. With options offering up to 6,912 ribbon and 5,184 single-fiber splice capacity, we can help support low-to-high-density networks.

Learn More

Enabling Your Transition Splice

Hardware Decisions

Hardware Decisions

Corning offers multiple OSE solutions. As a leader in innovation, whichever network design you choose, Corning hardware solutions deliver value to your transition splice.

Learn More

Ultra-High Density Splice Transitions

Ultra-High Density Splice Transitions

Supporting up to 6,912 ribbon or 5,184 single-fiber splice capacity can be difficult. Our ultra-density OSE helps manage fiber-rich splice transitions. 

Learn More

Mid-High Density Splice Transitions

Mid-High Density Splice Transitions

Our high-density OSE supports up to 4,320 ribbon splice and 3,240 single-fiber splice capacity. Learn more about the features and benefits.

Read More

Installation Best Practices for High-Density Splice Transitions

Installation Best Practices

We recognize that transitioning cable can be time-consuming. Our standard recommended procedures can help reduce the time required to deploy your OSE.

Learn More

Redefining Cable Transitions

OSE Cable Entry Best Practices

When managing transitions for dense cables, installation can be challenging and time-consuming. We can help! Check out our standard recommended procedures for cable entry with the OSE portfolio.

Learn More

Tools and Resources