• Date and Author: 03.09.2024 by Fredy Künzler
• Reading Time: 5 minutes
• Internet Subscription Parameters: Most providers advertise with maximum available bandwidth along with price. Two competing technologies for Internet connections in the past were DSL and cable Internet. DSL uses two-wire copper cable and has asymmetry with 100/20 Mbit/s (100 Mbit/s download, 20 Mbit/s upload). Cable Internet uses coaxial cable and the DOCSIS 3.1 standard can reach 10/1 Gbit/s in theory. Fiber optics has no such limits and is preferred by most network operators.
• Network Topologies: DSL has a P2P network topology and cable TV networks are P2MP. In fiber optics, earlier "Telefönler" used P2P and "Käbeler" used P2MP. XGS-PON is the predominant fiber optic topology based on PON and supports 10 Gbit/s symmetrical bandwidth split among 2 to 128 customers using an optical splitter. Most Swiss providers use 32-customer splitters.
• Network Devices: In the central office for XGS-PON, the device to aggregate customer lines is OLT. For example, the Nokia 7360 ISAM FX-8 has one or two supervisor cards with 4 x 10 Gbit/s Ethernet uplinks and 8 slots for XGS-PON line cards. Each line card has 16 10 Gbit/s connections.
• Overbooking: Ethernet on P2P network topology has a lower overbooking factor compared to P2MP. Providers use overbooking to accumulate bandwidth requirements. SmokePing can visualize overbooking by measuring latency. Overbooking is flexible but can lead to quality issues like jerky Netflix streams and lagging games when the network is overloaded during prime time.
• The Business of Internet Provider: The business works by accumulating bandwidth requirements and producing necessary capacity. Telemetry is used to evaluate traffic and send alerts. Periodic upgrades are necessary. Some customers may complain about "slow Internet" due to poor WiFi quality and should use an Ethernet cable for reliable speed tests.