What Is SVC in Telecom? Switched Virtual Circuit Explained

SVC is a temporary network connection established on demand. Unlike a Permanent Virtual Circuit (PVC), it exists only while data is being transmitted, making it flexible and cost-efficient for telecom networks.

SVC stands for Switched Virtual Circuit.

What Is SVC in Telecom?

In telecommunications, an SVC (Switched Virtual Circuit) is a temporary, on-demand network connection that exists only for the duration of a data session. Unlike permanent connections, it is established only when data needs to be transmitted and automatically disconnects once the transmission is complete.

Think of it like a dialled phone call — the connection is active while you’re communicating and disappears afterwards. This approach allows networks to provide a dedicated path for data without reserving resources all the time, making SVC flexible, cost-efficient, and efficient in bandwidth usage.

Key Characteristics of SVC

• Temporary: Created only when needed and disconnected after use.
• Dynamic: The network selects the best path for data in real time.
• Efficient: Frees resources once the session ends for optimal usage.

SVC is commonly used in telecom networks, enterprise systems, and ATM networks, where connections are needed temporarily rather than continuously. Its on-demand nature ensures that network resources are optimised while still giving the reliability of a point-to-point connection.

How Does a Switched Virtual Circuit Work?

1. Connection Request: The sending device signals the network to establish a session.
2. Path Setup: The network dynamically sets up a temporary route for the data.
3. Data Transmission: Information flows through this dedicated path while the session is active.
4. Termination: Once the transmission is complete, the circuit is automatically disconnected, freeing network resources.

What Are the Types of SVC?

Switched Virtual Circuits are mainly classified into two types based on how data is transmitted:

1. Circuit-Switched SVC

• A temporary dedicated path is established for the session.
• Ensures reliable communication, similar to traditional phone calls.

2. Packet-Switched SVC

• Data is sent in packets over a shared network, with paths allocated dynamically.
• Offers more flexibility and efficient use of network resources.

These types allow networks to choose the best approach depending on the application and traffic needs.

SVC vs PVC: What’s the Difference?

Switched Virtual Circuit (SVC) and Permanent Virtual Circuit (PVC) are both virtual connections, but they work differently:

In short:

• SVC is dynamic, temporary, and cost-efficient.
• PVC is fixed, continuous, and ideal for constant traffic.

What Are the Benefits of Using Switched Virtual Circuits?

• Cost-Efficient: Resources are used only when needed, reducing unnecessary expenses.
• Flexible Connections: Ideal for temporary or on-demand data sessions.
• Optimised Bandwidth: Frees network resources after each session, improving overall efficiency.
• Reliable Communication: Provides a dedicated path while the session is active, ensuring smooth data transfer.
• Scalable: Works well for networks with varying traffic loads, adapting to demand easily.

What Are the Real-Life Applications of SVC?

• Telecom Networks: Handling calls and data sessions that don’t need a permanent connection.
• ATM Networks (Asynchronous Transfer Mode): Efficiently transferring data in banking and enterprise systems.
• Enterprise VPNs: Providing temporary private network access for remote or on-demand work.
• Data Communication: Any scenario where bandwidth optimisation and resource efficiency are important.

SVC is ideal for situations where connections are needed occasionally, ensuring efficient use of network resources without sacrificing reliability.