Why are FTTP speeds asymmetric?

Is there an inherent technical limitation to why the Openreach FTTP products are all asymmetric?

From what I can see in other parts of the world, FTTP products are often symmetric as standard.

Generally speaking, most internet use is a small upload (the request for specific data) followed but a big download (the requested data being delivered)

This is, of course, an enormous over simplification, but kinda points in the right direction.

In reply to a post by pleasence:

Is there an inherent technical limitation to why the Openreach FTTP products are all asymmetric?

Because they want to be. Their competitors (Hyperoptic, Gigafast etc) are not.
I suspect it makes product comparison easier, but it is strange.

Yes internet access is tradtionally asymetric, but that is changing thanks to mobile devices that record 4K video, and people hosting games at home, and working from home uploading 500 Mb pictures or graphic models etc.

The GPON (ITU G.984) and XG-PON (ITU G.987)standards that Openreach are using are inherently asymmetrical. That said they are both 2:1, that is for example GPON is 2.4Gb/s down 1.2Gbps up shared over all the connected ONT's on an OLT. For XG-Pon it is 10Gb/s down and 2.5Gbps up shared.

As such when Openreach do a 330/50 product they have taken a deliberate decision to cripple the upload speeds. There is no reason why it should not be 330/165. Heck if they had kept to the 4:1 of FTTC it would be a much more attractive 330/80 product. The cynics (myself included) would suggest this is to protect their leased line business by crippling upload speeds.

Edited by jabuzzard (Thu 16-Jan-20 14:30:28)

The PON technology is asymmetrical, and keeping the retail services the same differentiates them from the leased line ethernet products.

In reply to a post by jchamier:

Because they want to be. Their competitors (Hyperoptic, Gigafast etc) are not.
I suspect it makes product comparison easier, but it is strange.

Wrong it is inherent in the standard they are using. I was under the impression that but Hyperoptic and Gigafast also use PON based networks so under contention they will be asymmetric too. You would have to deploy a P2P network like B4RN and some other alt nets or make sure you never oversold your bandwidth (seems highly unlikely) to genuinely be able to offer symmetric speeds with PON. My guess is Gigafast and Hyperoptic oversell their upload speed in the knowledge that most people don't use it so everything is fine till it's not.

Yes internet access is tradtionally asymetric, but that is changing thanks to mobile devices that record 4K video, and people hosting games at home, and working from home uploading 500 Mb pictures or graphic models etc.

Wrong again, domestic internet access has at times been asymmetric but in general internet access has always been symmetric.

Thanks for all the responses on this.

In reply to a post by jabuzzard:

The GPON (ITU G.984) and XG-PON (ITU G.987)standards that Openreach are using are inherently asymmetrical. That said they are both 2:1, that is for example GPON is 2.4Gb/s down 1.2Gbps up shared over all the connected ONT's on an OLT. For XG-Pon it is 10Gb/s down and 2.5Gbps up shared.

As such when Openreach do a 330/50 product they have taken a deliberate decision to cripple the upload speeds. There is no reason why it should not be 330/165. Heck if they had kept to the 4:1 of FTTC it would be a much more attractive 330/80 product. The cynics (myself included) would suggest this is to protect their leased line business by crippling upload speeds.

This is interesting, I didn't know the GPON standard had that 2:1 ratio.

Has there ever been official comment from Openreach or a govt department on this? Seems like a question journalists should be asking when our FTTP services are being claimed as world class, but we artificially limit a 10/1 ratio.

It seems like an important issue as more people work from home. My guess is Openreach are still very much in the mindset that domestic internet is about consumption (Netflix, Youtube etc.) and no home user would ever have need for more than 30mbps up.

Hyperoptic is NOT PON based. They are dedicated circuits to the building and then fibre to the floor and Gigabit Ethernet into each apartment (or GigE from basement if distances are short enough).

Don't forget the GPON split, some UK GPON firms use 32 some go all the way to 128.

In reply to a post by jabuzzard:

Wrong it is inherent in the standard they are using. I was under the impression that but Hyperoptic and Gigafast also use PON based networks so under contention they will be asymmetric too. You would have to deploy a P2P network like B4RN and some other alt nets or make sure you never oversold your bandwidth (seems highly unlikely) to genuinely be able to offer symmetric speeds with PON. My guess is Gigafast and Hyperoptic oversell their upload speed in the knowledge that most people don't use it so everything is fine till it's not.

Thanks. I thought they were all using the same as B4RN.

Wrong again, domestic internet access has at times been asymmetric but in general internet access has always been symmetric.

Colloquial speech on a forum primarily aimed at broadband (aka domestic) access. Dialup was symmetrical until 56k, agreed, and business connections were always symmetric. agreed.

It is a product choice, some UK GPON providers use symmetric, some don't. The same around the rest of the world, so are very much in the same class.

Some providers around world have also done 2 Gbps GPON download in the past too.

The Gig Openreach is set to be 1000 down, 220 up which does not look much of an impediment to working from home, unless you are moving uncompressed HD material around but that needs well over 1 Gigabit anyway.