A central office switch is network equipment that connects telephone lines and trunks so calls can begin, end, or travel through the public switched telephone network (PSTN). It may serve end users directly, connect other switches, or perform both roles. The term refers to the switching system—not necessarily the building that houses it.
What a central office switch does
The switch interconnects lines and trunks to route calls. Depending on its role, it can connect an end user’s telephone service to the network or switch trunk circuits between other central-office switches. A U.S. interconnection agreement defines a central-office switch as equipment used to provide telecommunications services, including end-office and tandem switches, and allows for a combination of the two functions (SEC-hosted interconnection agreement).
As an Amazon Associate I earn from qualifying purchases.
End-office and tandem switch roles
| Role | Connections handled | What it means |
|---|---|---|
| End office | End-user exchange service and the network | The user-facing switching role. Federal regulation defines an end office as “the telephone company office from which the end user receives exchange service” (47 CFR § 69.2, via Cornell Legal Information Institute). |
| Tandem office | Trunk circuits between central-office switches | The intermediary role: it connects or switches trunks among switches. |
| Combination switch | Both end-user exchange service and trunks between switches | A single switch can carry out both end-office and tandem functions. |
The Florida Public Service Commission also distinguishes end offices by their connection to end-user exchange service and tandem offices by their switching of trunk circuits among central-office switches (Florida Public Service Commission order). These are functional roles; they do not necessarily correspond to separate buildings.
Central office versus central office switch
“Central office” can refer to switching equipment or, in some usage, the telephone-company building where switching systems and related equipment are installed. “Central office switch” is more precise: it identifies the switching equipment or system. The SEC-hosted agreement makes this distinction in its definitions, while noting that a central office may handle several central-office codes (“NXX”); that statement is specific to the agreement, not a universal count or rule.
#1 Best Overall
- Elegant design ,easy for programming and installation
- Programming is through normal phone
- All basic features of a phone system is included
- Caller ID
- call transfer
How to read the term in context
- If the passage concerns service provided to a subscriber, it is likely referring to the end-office role.
- If it describes trunks connecting multiple switches, it is referring to the tandem role.
- If it refers to a location, building, or facility, “central office” may mean the site rather than the switching system.
Regulatory and interconnection documents define these terms for their particular contexts. They establish the basic switching roles, but do not establish one universal physical layout or identify which technologies a particular carrier currently uses.
Quick Recap
Best Value
- This set includes two parts:
- #1. An on/off switch with phone cords coming out of each side
- #2. An adapter to add it to your existing phone cord
- Just connect it to your phone cord, then flip the switch to turn your phone on or off during naps, meals, etc.
- Works with landline and cordless phones.
Rank #4
- New generic 2 Ports RJ11 RJ12 Manual Sharing Switch Box, Hot-swappable (no need to reboot computer)
- 6P6C female connector, 2 manual switch buttons
- 2 Ports RJ11 RJ12 Switch Box
- High quality rotary switch,No power required No additional software needed Easy to use and install
- Cable not included**
Rank #3
- Command fax switch
- Single line fax switch (line sharing device)
- Phone, fax, answering machine, and computer can share one phone line
- Alerts you to incoming calls/faxes while online
- Distinctive ring detection (switches automatically to fax)
Rank #2
- 2 CO Lines x 8 Extensions,Automated Telephone System.
- This SOHO-PBX SP-208 system is an ideal telephone system for small offices and home offices. It is very easy to install and use.
- It has all the standard features comparable to those expensive PBX systems in the market. It works with your current analog phones and you do not need to spend extra money to buy proprietary telephones to work with the PBX.
- The SP-208 is your ideal small or home office receptionist. It is features packed and comes with an easy to follow instruction booklet.
- With the design and production according to G.712 and G.732 protocol of CCITT, this system integrates virtues of various practical function of PABX, and it has unique advantage in innovation.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
