Cable Forum - View Single Post - 2G 2Gbps now officially available in HFC areas

homesecurity · Today, 01:51

Spot on regarding the CAPEX reality. Coming from the physical cabling and field installation side, squeezing 2Gbps out of legacy HFC rather than completing the full Project Mustang XGS-PON overbuild makes total balance-sheet sense for Liberty Global, but on the ground it introduces some very interesting physical plant challenges:

1. The Physical Coax Bottleneck (Drop Cables & Isolators)
To push 2Gbps downstream on DOCSIS 3.1, VM has to push OFDM carrier spectrum right up to 1.0GHz / 1.2GHz. While modern WF100/RG6 can handle that fine over short runs, out in the street cabinets and domestic brown omni-boxes you regularly encounter 20-to-30-year-old Telewest/NTL drop leads, corroded galvanized f-connectors, and legacy Technetix ground isolators. At 800MHz–1GHz, the high-frequency attenuation curve steepens drastically. We see properties where 1Gbps was rock solid, but negotiating full 2Gbps profiles triggers forward error correction (FEC) errors because the physical drop cable simply doesn't have the SNR margin at the top of the band without a repull.

2. The Upstream Asymmetry Gap
Downlink marketing numbers look great at 2Gbps, but on HFC the elephant in the room remains the upstream. Without high-split (204MHz) or full DOCSIS 4.0 upgrades to street taps and line amplifiers, HFC is still choked on sub-split/mid-split OFDMA. Getting 2000Mbps down with ~100-150Mbps up is a huge disparity compared to native XGS-PON altnets offering symmetrical 2Gbps/2Gbps. For domestic multi-user homes with cloud backups, remote camera sync, and NAS transfers, that upstream bottleneck becomes obvious very quickly.

3. The Internal 1Gbps 'Bottleneck Wall'
As Carth rightly noted earlier, delivering 2Gbps to the Hub 5/5x port is only half the battle. Because the Hub only has a single 2.5Gbps port (with the remaining three capped at standard 1Gbps), 95% of domestic setups hit a brick wall. Unless the homeowner runs Cat6/Cat6a into a multi-gig 2.5GbE managed switch and has 2.5G NICs or clean 160MHz Wi-Fi 6E/7 channels, they literally cannot pull more than 940Mbps on any single device.

If Mustang really is paused on the VM balance sheet, DOCSIS 3.1 will have to carry the heavy water for several years to come. It’s remarkable how much bandwidth they've managed to wring out of copper coax originally pulled in the 1990s!

Today, 01:51	#19
homesecurity Mr Gary Pearce Join Date: Nov 2026 Location: United Kingdom Services: TV INternet CCTV Home security Alarms Hikvision Dahua Ajax Posts: 6	Re: 2Gbps now officially available in HFC areas Spot on regarding the CAPEX reality. Coming from the physical cabling and field installation side, squeezing 2Gbps out of legacy HFC rather than completing the full Project Mustang XGS-PON overbuild makes total balance-sheet sense for Liberty Global, but on the ground it introduces some very interesting physical plant challenges: 1. The Physical Coax Bottleneck (Drop Cables & Isolators) To push 2Gbps downstream on DOCSIS 3.1, VM has to push OFDM carrier spectrum right up to 1.0GHz / 1.2GHz. While modern WF100/RG6 can handle that fine over short runs, out in the street cabinets and domestic brown omni-boxes you regularly encounter 20-to-30-year-old Telewest/NTL drop leads, corroded galvanized f-connectors, and legacy Technetix ground isolators. At 800MHz–1GHz, the high-frequency attenuation curve steepens drastically. We see properties where 1Gbps was rock solid, but negotiating full 2Gbps profiles triggers forward error correction (FEC) errors because the physical drop cable simply doesn't have the SNR margin at the top of the band without a repull. 2. The Upstream Asymmetry Gap Downlink marketing numbers look great at 2Gbps, but on HFC the elephant in the room remains the upstream. Without high-split (204MHz) or full DOCSIS 4.0 upgrades to street taps and line amplifiers, HFC is still choked on sub-split/mid-split OFDMA. Getting 2000Mbps down with ~100-150Mbps up is a huge disparity compared to native XGS-PON altnets offering symmetrical 2Gbps/2Gbps. For domestic multi-user homes with cloud backups, remote camera sync, and NAS transfers, that upstream bottleneck becomes obvious very quickly. 3. The Internal 1Gbps 'Bottleneck Wall' As Carth rightly noted earlier, delivering 2Gbps to the Hub 5/5x port is only half the battle. Because the Hub only has a single 2.5Gbps port (with the remaining three capped at standard 1Gbps), 95% of domestic setups hit a brick wall. Unless the homeowner runs Cat6/Cat6a into a multi-gig 2.5GbE managed switch and has 2.5G NICs or clean 160MHz Wi-Fi 6E/7 channels, they literally cannot pull more than 940Mbps on any single device. If Mustang really is paused on the VM balance sheet, DOCSIS 3.1 will have to carry the heavy water for several years to come. It’s remarkable how much bandwidth they've managed to wring out of copper coax originally pulled in the 1990s!