A telco tells me they are getting impressive early results from the Calix 48 port DSLAM with the new Sckipio 212 MHz chips. There still is work to do but this is encouraging.
Carriers want DSLAMs with more than 16 ports to reduce the deployment costs from the basement or larger field cabinets. Speed matters to the marketing side of the company; AT&T's CEO believes he must offer a true gigabit to match cable. (They've been getting ~750 megabits with first generation chips.
BT has been one of the strongest demanding more than the original 16 ports. They are deploying first generation G.fast from the existing cabinets, accepting they can only offer 330 megabits because of distances. The cabinets connect more homes, increasing the number of ports they need. They have been using Huawei;s external vectoring unit for 48 ports and I believe now 96 ports.
Now, both Broadcom and Sckipio have demonstrated their 212 MHz chips, acknowledging improvements will be needed before deployment. Vectoring 16 ports at 1.5 gigabits is a challenge; 48 and 96 is even tougher.
The second generation 212 chips are designed for cDTA, allowing switching individual lines from download to upload. This effectively increases upstream speed substantially.
They also support reverse power, drawing the power they need from the customers' homes rather than a grid connection. This is particularly important as carriers start deploying to distribution points near homes. That's straightforward on existing poles or in pits that are ready. Neither is likely to have power installed.
The industry is watching closely for which chip vendor first is ready for large deployments.