Throughput and dup acks

[ahmad82pkn]

Hi,

We are having some weird issue, where throughput is very low 2MB/sec between two hosts over the Single Model Fiber WAN link.

On investigation, its found that our carrier port is configured as 10G/Auto negotiate and negotiating in 10G and my side Cisco ISR 4431 is negotiating in 1G.

First of all I dont know why they are able to negotiate this way.

Second question if one side is negotiated as 10G(carrier) and other side is 1G(me) , can it cause performance issues ? I am seeing low throughput and Dup acks in wireshark.

[Tom Randstrom]

10G optical transceivers do not negotiate to 1G speeds.  Please provide additional details regarding the optical transceivers being utilized on each end of the link. I suspect there are higher layer issues causing the reduced through-put.