T568A vs T568B Wiring Guide San Francisco | Local Cabling Expert Tips
If you’re setting up or upgrading network cabling in your San Francisco property, you’ve likely come across two color-coded wiring standards: T568A and T568B. Both are industry-approved configurations used for Ethernet cabling, yet many homeowners, IT technicians, and contractors still wonder — which one is better for me?
This guide breaks down the differences, applications, and local insights to help you choose the right wiring standard for your project in San Francisco.
Understanding the Basics of T568A and T568B
Both T568A and T568B are pinout configurations for RJ45 connectors — the small plugs found at the ends of Ethernet cables. They determine how the eight individual wires inside a Cat5e, Cat6, or Cat6A cable are arranged.
- T568A Standard: Traditionally used in residential networks and recommended by federal standards.
- T568B Standard: Common in commercial installations and older networking infrastructures across the U.S.
In terms of performance, both are identical. The main difference lies in the wire color order.
T568A Color Code
- White/Green
- Green
- White/Orange
- Blue
- White/Blue
- Orange
- White/Brown
- Brown
T568B Color Code
- White/Orange
- Orange
- White/Green
- Blue
- White/Blue
- Green
- White/Brown
- Brown
Key Difference Between T568A and T568B
| Feature | T568A | T568B |
|---|---|---|
| Wire Pairing | Green pair on pins 1 and 2 | Orange pair on pins 1 and 2 |
| Common Usage | Residential / government | Commercial / legacy installs |
| Compatibility | Works with older phone wiring | Matches AT&T 258A standard |
| Performance | Equal | Equal |
| Recommended For | Newer home networks | Existing business networks |
Choosing the Right Standard in San Francisco
When wiring a building in San Francisco, consistency is key. Mixing both standards in one network can cause communication errors or connection drops.
Here’s how to choose:
- For new residential projects: Go with T568A, as it aligns with current cabling standards (TIA/EIA-568-C).
- For existing office or commercial rewiring: Stick with T568B if that’s already used throughout the system.
- For PoE (Power over Ethernet) devices: Either standard works, as long as both ends match.
Local San Francisco contractors often select T568B because many commercial properties and co-working spaces still use legacy T568B wiring from earlier telecom setups.
Local Insights: Cabling Trends in San Francisco
San Francisco’s diverse mix of historic buildings, modern tech offices, and high-density housing means cabling requirements vary greatly.
- Historic residential units (Mission District, Nob Hill): Often need rewiring for data networks — T568A preferred for new installs.
- Tech offices (SoMa, Financial District): Typically maintain T568B to match older commercial standards.
- Green and smart buildings (Mission Bay, Dogpatch): Commonly use T568A with Cat6 or Cat6A cables for high-speed PoE systems.
Why Consistency Matters
If one end of your cable uses T568A and the other T568B, you’ve created a crossover cable — which may work only for specific network devices and not for general Ethernet connections.
For structured cabling in offices, retail spaces, or smart homes, ensure both ends are wired the same way to maintain full-speed data flow.
Professional Cabling Tip
San Francisco’s local codes and building standards emphasize low-voltage compliance and safety. Always hire a licensed low-voltage contractor who understands both California electrical code and network wiring best practices.
They can also test your cable runs for signal loss and verify compliance with local and federal TIA standards.
Conclusion
Choosing between T568A and T568B isn’t about speed — it’s about compatibility, consistency, and compliance.
For San Francisco homeowners, T568A is the modern standard that ensures long-term reliability. For businesses and older commercial properties, T568B may still be the practical choice.