How do phone numbers route calls across different networks?
Posted: Wed May 21, 2025 5:20 am
Phone numbers are the linchpin of call routing across different networks, acting as the precise address that guides a call from its origin to its intended destination, often spanning multiple telecommunication providers and geographic regions. This complex process relies on a hierarchical structure of the phone number itself and sophisticated network infrastructure.
Here's a step-by-step breakdown of how phone numbers facilitate call routing across different networks:
Originating Call Initiation and Number Dialing:
When a caller dials a phone number, their belgium number database local exchange (for landlines) or their mobile switching center (for mobile phones) immediately recognizes the dialed digits. The phone number becomes the primary routing instruction.
Initial Analysis: Local, Long-Distance, or International?
The originating network (the caller's carrier) first analyzes the dialed phone number to determine its nature:
Local Call: If the number falls within the same local exchange area, the call may be handled entirely within the originating carrier's local network.
National Long-Distance Call: If the number is in a different area code but within the same country, the call needs to be routed through national long-distance networks.
International Call: If the number begins with an international country code (or a '+' symbol indicating one), the call needs to be routed to a different country's telecommunications network.
Routing Based on Number Components:
International Calls (Country Code - E.164):
If the dialed number is international, the originating network first identifies the country code (e.g., +880 for Bangladesh from a US phone).
It then routes the call to an international gateway switch. These are specialized exchanges that connect national networks to the global telecommunications infrastructure.
The international gateway uses the country code to determine which destination country's international gateway to forward the call to. This might involve transmitting the call over fiber optic cables, satellite links, or other international telecommunication routes.
National Calls (Area Code/National Destination Code):
Once the call reaches the destination country's network (or if it's a domestic long-distance call), the next routing decision is based on the area code or national destination code.
This code directs the call to the appropriate regional exchange or specific network (e.g., distinguishing between a Grameenphone number and a Robi number in Bangladesh if the area code or prefix is specific to an operator, or directing to a specific city's exchange for landlines).
Local Calls (Local Subscriber Number):
Finally, within the identified area code or network, the local subscriber number is used to pinpoint the exact communication endpoint.
Here's a step-by-step breakdown of how phone numbers facilitate call routing across different networks:
Originating Call Initiation and Number Dialing:
When a caller dials a phone number, their belgium number database local exchange (for landlines) or their mobile switching center (for mobile phones) immediately recognizes the dialed digits. The phone number becomes the primary routing instruction.
Initial Analysis: Local, Long-Distance, or International?
The originating network (the caller's carrier) first analyzes the dialed phone number to determine its nature:
Local Call: If the number falls within the same local exchange area, the call may be handled entirely within the originating carrier's local network.
National Long-Distance Call: If the number is in a different area code but within the same country, the call needs to be routed through national long-distance networks.
International Call: If the number begins with an international country code (or a '+' symbol indicating one), the call needs to be routed to a different country's telecommunications network.
Routing Based on Number Components:
International Calls (Country Code - E.164):
If the dialed number is international, the originating network first identifies the country code (e.g., +880 for Bangladesh from a US phone).
It then routes the call to an international gateway switch. These are specialized exchanges that connect national networks to the global telecommunications infrastructure.
The international gateway uses the country code to determine which destination country's international gateway to forward the call to. This might involve transmitting the call over fiber optic cables, satellite links, or other international telecommunication routes.
National Calls (Area Code/National Destination Code):
Once the call reaches the destination country's network (or if it's a domestic long-distance call), the next routing decision is based on the area code or national destination code.
This code directs the call to the appropriate regional exchange or specific network (e.g., distinguishing between a Grameenphone number and a Robi number in Bangladesh if the area code or prefix is specific to an operator, or directing to a specific city's exchange for landlines).
Local Calls (Local Subscriber Number):
Finally, within the identified area code or network, the local subscriber number is used to pinpoint the exact communication endpoint.