ECI & Retransmission

The planned re-introduction of retransmission on ECI estate was due for next month, but I've been informed that this is now not likely to happen. During testing of the updated ECI firmware (which will retrain a line if it becomes 'stuck' due to noise being generated on the line), unrelated issues were found which are now being resolved between ECI and Openreach. This means the likely updated firmware due next month is now going to be held back.

No timescales are given or what the unrelated issues are, but I will update if they are released.

disappointing news.. but thanks for keeping us updated Andy

Not good to find a new issue, but there's no surprise that finding *anything* means the rollout is put on hold.

Is this upstream, downstream or both?

Having been playing with upstream QOS recently on an ECI cab + ECI OR modem, it seems I can get it close to perfect allowing for PTM overheads (unlike with an unlocked Huawei which does some clunky QOS of it's own even if you turn off the explicit QOS). Of course the ECI will also do some fairness - but it seems to be accurate.

I don't know how retrans works in practice, eg. is it out of band from advertised sync, or would a close set QOS setup have to back off some unknown amount to deal with variable bandwidth?

In reply to a post by legume:

I don't know how retrans works in practice, eg. is it out of band from advertised sync,

Retransmission happens using the advertised sync, not out-of-band, which obviously can result in a loss of effective bandwidth.

With retransmission activated, the modems report a "minEFTR" value, which is the minimum effective throughput rate seen recently. I guess if you run QoS too closely, you might need to adjust dynamically based on this value.

In reply to a post by WWWombat:

In reply to a post by legume:

I don't know how retrans works in practice, eg. is it out of band from advertised sync,

Retransmission happens using the advertised sync, not out-of-band, which obviously can result in a loss of effective bandwidth.

With retransmission activated, the modems report a "minEFTR" value, which is the minimum effective throughput rate seen recently. I guess if you run QoS too closely, you might need to adjust dynamically based on this value.

Ok, thanks for the info, shame it's in band though.

I guess it's not happening soon for me anyway (using locked down ECI so can't see anything stats wise).