How does a Internet Subscriber's traffic Flow travel from Service Provider Perspective
How does a Subscriber’s Internet Traffic Flow#
As with everything it depends on the solution provided:
- Fibre
- Adsl
- Wireless technology - 3g, 4g and LTE
Looking from a Fibre perspective the flow is:
ONT (GPON or PON) -> OLT -> ENNI -> BNG (mediating with RADIUS) -> PACKET INTROSPECTION - P ROUTER - PEERING/IP TRANSIT
Infrastructure providers:
- segments traffic into vlans
- radius credentials
- send variables attached to the username
BNG (Border Network Gateways) - mediates between ENNI and Radius to provide service
ONT (Optical Network Terminal) tags all traffic from certain address
ip address allocated out of radius
Sandvine packet introspection enforces the cap
Can split radius servers into different environments - on every authentication attempt BNG tells radius the amount of data users - sandvine dynamic ip is just done with ease
Underlying fiber provider - .1q tunnel means it all goes (service vlan id)
So let us go through what the above are:
- ONT (Optical Network Terminal) - device at subscriber’s home that converts optical signals into electrical signals
- OLT (Optical Line Terminal) - convert, frame, and transmit signals for the PON network and to coordinate the optical network terminals multiplexing for the shared upstream transmission
- ENNI (External Network-to-Network Interface) - The boundary between 2 operators. Layer 2 Vlan is handed off.
- Radius - Speaks to the BNG to authenticate subscribers
- BNG (Broadband Network Gateway) - the access point for customers to connect to the broadband network
- PACKET INTROSPECTION - Inspects all traffic and stores amount of traffic used for subscribers
- P ROUTER (Provider Router) - Provide reachability between Provider Edge devices
- PEERING / IP TRANSIT - IP transit is when one entity pays another for the right to transit its upstream network (One entity is higher than the other on the chain). IP peering is a mutual exchange of data between two ISPs.