I can give an anecdotal reply, since I've never ran those types of facilities myself..
My understanding is that in general the main exchanges (the ones in cities, formerly tandem exchanges and /possibly/ the equivalent by cable) would have generator backup as they are run as high availability data centres, meaning they drop to battery for a minute then generators kick in for as long as they are fed fuel... in theory indefinitely unless there is severe emergency in the area. In the more rural locations I've not heard of generators being used and think they are UPS driven, so from minutes upwards but not stretching into hours. I would assume street cabinets either have no backup power or some basic batteries at best - at least the ones I've seen inside don't appear to have anything of note aside the telco gear. Someone with first hand knowledge would be better placed to answer, but in the absence of that, the above is my experience from, well, quite some time ago but I don't see why it would have changed.. HTH Steve On Sat, 4 Feb 2023 at 15:44, Brandon Butterworth <bran...@bogons.net> wrote: > On Fri Feb 03, 2023 at 03:16:28PM -0800, Leo Vegoda wrote: > > > Question is, how much battery runtime can I typically expect from ISPs' > > > last mile infra. I was hoping some of you here might help estimate from > > > own experience. > > > > Ofcom ran a consultation on this in 2011. They suggested a minimum of > > one hour battery backup. My reading is that that is what they went > > with but the Ofcom site doesn't make that sparklingly clear, so I > > could be wrong. I'm also not sure if whatever obligation they came up > > with in 2011 has been updated. > > Survey says 1 hour? It is academic what people think when there is an > actual plan for <checks notes> rolling 3 hour outages several times per day > > https://www.gov.uk/government/publications/electricity-supply-emergency-code > > So not only do you need to plan for the down time you need to consider the > recovery time of your system. Lead based systems will take many times > the run time to recharge and may not be ready for the next outage. Thus > LiFePo4 batteries are the way to go, we can recharge at more than our > discharge rate. > > Without rolling blackouts we have already had this problem with normal > rural > supply. We had many multi hour outages and concluded we need 6 to 8 hours > capacity if we wish to operate through them. That also allows time to find > the nature of the fault, the likely resolution time and for someone to take > a generator to site (perhaps multiple sites) if needed. > > Due to the reach of fibre and FWA it is normal for our power to go down > while some customers are on a feed that is up, so it is not pointless > keeping our sites running. > > We sent this note to our customers > https://www.dropbox.com/s/zvleyj0epqzne5y/20221103_winter_power.pdf?dl=0 > so they can choose based on their needs rather than part fixing the > problem for them, having just internet may not be sufficient for many. > > It is a bit late to be worrying about rolling blackouts this winter as the > threat has reduced and by the time a solution is deployed at scale it will > be spring or summer. > > brandon > > > -- Stephen Wilcox BSO | IX Reach E: step...@ixreach.com M: +44 7966 048633 <+44%207966%20048633> M: +1 305 613 9492 <(305)%20613-9492> -- *CONFIDENTIALITY AND DISCLAIMER NOTICE: * This email is intended only for the person to whom it is addressed and/or otherwise authorized personnel. The information contained herein and attached is confidential. If you are not the intended recipient, please be advised that viewing this message and any attachments, as well as copying, forwarding, printing, and disseminating any information related to this email is prohibited, and that you should not take any action based on the content of this email and/or its attachments. If you received this message in error, please contact the sender and destroy all copies of this email and any attachment. Please note that the views and opinions expressed herein are solely those of the author and do not necessarily reflect those of the company. While antivirus protection tools have been employed, you should check this email and attachments for the presence of viruses. No warranties or assurances are made in relation to the safety and content of this email and attachments. The Company accepts no liability for any damage caused by any virus transmitted by or contained in this email and attachments. No liability is accepted for any consequences arising from this email. *AVIS DE CONFIDENTIALITÉ ET DE NON RESPONSABILITE* : Ce courriel, ainsi que toute pièce jointe, est confidentiel et peut être protégé par le secret professionnel. Si vous n’en êtes pas le destinataire visé, veuillez en aviser l’expéditeur immédiatement et le supprimer. Vous ne devez pas le copier, ni l’utiliser à quelque fin que ce soit, ni divulguer son contenu à qui que ce soit. BSO se réserve le droit de contrôler toute transmission qui passe par son réseau. Veuillez noter que les opinions exprimées dans cet e-mail sont uniquement celles de l'auteur et ne reflètent pas nécessairement celles de la société. Bien que des outils de protection antivirus aient été utilisés, vous devez vérifier cet e-mail et les pièces jointes pour toute présence de virus. Aucune garantie ou assurance n'est donnée concernant la sécurité et le contenu de cet e-mail et de ses pièces jointes. La Société décline toute responsabilité pour tout dommage causé par tout virus transmis par ou contenu dans cet e-mail et ses pièces jointes. Aucune responsabilité n'est acceptée pour les conséquences découlant de cet e-mail.
