connecting 1gig switches with 10gig uplinks

[CrackedJack1]

As the subject says, I need to connect 1gig switches via 10gigs while going through a wan emulator. There will be senders and receivers on both sides of the 10gig.

Examples:

1 sender connected @ 1gig > 10gig uplink > wan emulator > 10 gig uplink > 1 receiver connected @ 1gig
multiple senders connected @ 1 gig > 10gig uplink > wan emulator > 10 gig uplink > 1 receiver connected at 1gig (total throughput less than 1gig)
multiple senders connected @ 1 gig > 10gig uplink > wan emulator > 10 gig uplink > multiple receivers connected at 1gig

Should I be concerned that the 10gig uplink will forward the packets faster than the receiving switch can accept them and more than buffers can handle? (ignoring the impact of the wan emulator)

At the moment the switches involved are 3850's but that may change (at least on one side of the 10gig uplink). After seeing how the 3850 has limited capacity to handle bursts (doing some tests with some of our internal apps), I'm just afraid the receivers on the 2nd 3850 might get overwhelmed by traffic coming in via the 10gig link.

The traffic destined for a particular 1gig port won't be over a gig (except the occasional burst) so I'm not going to overwhelm the port but I'm not sure what the impact of having that 10gigs uplink will. Will it overload the 1gig port? Any info on what I can expect is appreciated.

Thanks

[sk.lachica]

Hi Crackedjack1,

In my opinion, when you have links that have different bandwidth capacities, the lowest bandwidth along the path is considered as the actual bandwidth of that path.

Note that you have 1G and 10G. Usually, in customer deployments, this is not a big deal unless you are sending more than 1Gbps of traffic. If you are, the excess traffic will undergo interface queueing, qos, etc., but otherwise, these will get dropped if you exceed 1Gbps.

[CrackedJack1]

Hi sk,

I noticed an error in my original post: the receivers are connected at 1gig, not 10 (original post has been corrected)

would your comments still apply? if I have a bunch of senders sending data that adds up to 2 gigs for example, but no receiver is getting more than 1gig, would my setup be ok? I'm just afraid the 10gig can send stuff so fast is overwhelms the 10gig uplink on the receiving 3850 and the receiving 3850 sends data too fast to the 1gig ports (even though those 1gig ports will only be receiving 100 or 200 Mbps, well below 1gig)