
➣ Introduction
In high-speed networking, the WAN Interface Sublayer (WIS) plays a pivotal role in adapting 10 Gigabit Ethernet (10GbE) for wide area network (WAN) environments. By enabling compatibility with SONET/SDH networks, WIS allows Ethernet frames to be transmitted efficiently over long-distance carrier infrastructures. Understanding WIS is essential for network engineers, IT professionals, and enterprises that deploy 10GbE networks with WAN requirements.
LINK-PP’s 10G optical modules, such as 10GBASE-LR SFP+, fully support WIS functionality, ensuring seamless operation in both LAN and WAN PHY modes.
➣ What is the WAN Interface Sublayer (WIS)?
The WAN Interface Sublayer (WIS) is a functional layer defined in the IEEE 802.3ae standard for 10 Gigabit Ethernet. Its primary purpose is to adapt standard Ethernet frames for transmission over SONET/SDH networks, which operate at slightly lower line rates than LAN PHY.
Key Functions of WIS:
Frame Encapsulation: WIS encapsulates standard Ethernet frames into a SONET/SDH-compatible format, enabling smooth interoperability with carrier networks.
Data Rate Adaptation: While LAN PHY runs at 10.3125 Gbps, WIS adjusts the data rate to 9.953 Gbps, aligning with OC-192/STM-64 standards.
Error Detection: Provides additional integrity checks to ensure data consistency during long-distance transmission.
Compatibility: Bridges the gap between enterprise LAN environments and WAN infrastructures, maintaining reliable 10GbE connectivity.

➣ WIS in WAN PHY Applications
WAN PHY is designed for Ethernet deployment over carrier networks. WIS is a critical component of WAN PHY, enabling Ethernet frames to traverse SONET/SDH links.
Benefits of WIS in WAN PHY:
Carrier Network Integration: Ensures 10GbE signals can be transmitted over existing telecommunication backbones.
Long-Distance Transmission: Supports connections spanning tens of kilometers while preserving signal integrity.
Flexible Deployment: Works with LINK-PP optical modules to switch between LAN PHY and WAN PHY as needed.
LINK-PP 10GBASE-LR SFP+ modules implement WIS, making them ideal for enterprise-to-carrier connections, metro networks, and WAN deployments requiring both high performance and compatibility.
➣ Technical Overview
Feature | Description |
---|---|
Standard | IEEE 802.3ae |
Data Rate (LAN PHY) | 10.3125 Gbps |
Data Rate (WAN PHY with WIS) | 9.953 Gbps (OC-192/STM-64 alignment) |
Function | Encapsulation of Ethernet frames for SONET/SDH |
Application | WAN PHY, carrier networks, metro, and long-distance links |
➣ Conclusion
The WAN Interface Sublayer (WIS) is a crucial component for extending 10 Gigabit Ethernet into wide-area networks. By enabling LAN-to-WAN adaptation, frame encapsulation, and rate alignment with SONET/SDH, WIS ensures reliable, high-speed data transmission across carrier networks.
LINK-PP’s 10G optical modules support WIS and WAN PHY modes, providing network engineers with the flexibility to deploy 10GbE links in both local and wide area environments.