More bandwidth than MX can handle

[MattS]

I find myself in a position I never anticipated and I'm unsure how to proceed. Due to the rapid expansion of fiber in our area and price drops, I'm shopping for a new circuit. I've found myself in a position where I have 2 year old MX84's that were MORE than sufficient for our 100Mbps circuit, but now are not going to be able to handle the 1Gbps fiber line that is half the price we were previously paying for a 100Mbps circuit. Has anyone run into this? My questions are as follows.

1. I know the MX84 maxes out at 500Mbps on a good day. What is the behavior if it's overloaded?
2. Can the QoS artificially restrict bandwidth usage of the circuit so performance of the units isn't adversely affected?
3. What are some other ideas for throttling this?
4. Who ever thought a 1G fiber line would be cheaper than a 100M copper line? (rhetorical of course)

[Adam · Accepted solution]

I created a similar thread to this not long ago.  The MX will just limit to a little over its max capacity.  I have a MX64 on a Gig burstable circuit and I only get between 250-300M.  You probably don't need to restrict but it wouldn't be a bad idea to set the bandwidth on the traffic shaping page to the max the MX supports to err on the side of caution.  

[PhilipDAth]

@Adam is right, the MX will limit the performance to a level where it will operate correctly.  So you can happily plug in a much faster circuit.  You wont be able to use its full capacity, but the MX will operate without issue on it.

[MRCUR]

Keep in mind that you cannot actually set the uplink speed in Dashboard higher than the MX is configured to work with. An MX64 for instance will not let you set it to higher than 250Mbps while an MX450 will not let you set it to higher than 6Gbps. 

[MattS]

Thanks @Adam and @PhilipDAth

@MRCUR, I appreciate the caution but I'm not concerned about pushing the envelope. I was concerned that the MX would not throttle a 1G connection appropriately and we'd end up signing a new contract for 36 months, that would require purchasing replacement equipment when the pair of 84's I have are still more than enough for the office behind them.