That is incorrect the amplifiers have the capacity to amplify lots of channels simultaneously. So it is sufficient to only upgrade the endpoints (unless your fi

That is incorrect the amplifiers have the capacity to amplify lots of channels simultaneously. So it is sufficient to only upgrade the endpoints (unless your fibre is full, where full means the bandwidth of the amplifiers, ~100 Tb/s for a single fibre). This has in fact been the driver behind the tremendous growth in data rates we have seen in the last 30 years. Operators can incrementally upgrade links by upgrading the endpoints. To transfer a MB across the network was 100s of $ in the 90s and is now essentially free (it's like 10e-4 cents or sol