In a data center project, S7700 switches only have 10GE interface cards, and the upstream USG5100 devices only have GE combo interfaces. To enable communication between the S7700 switches and USG5100 devices, S5700 switches are deployed between them to connect the 10GE optical interfaces of the S7700 switches and GE electrical interfaces of the USG5100 devices.
Deploying the S5700 switches increases failure points on the network. Besides, to manage the S5700 switches, S7700 interfaces connected to the S5700 switches are configured as trunk interfaces and assigned a management VLAN, which complicates the configuration. The customer cannot accept this solution.
Install GE SFP optical transceivers on 10GE interfaces of the S7700 switches and connect the interfaces to GE optical interfaces of the USG5150 devices. This saves the need to deploy S5700 switches between the S7700 switches and USG5150 devices.
To connect 10GE SFP+ interfaces on some interface cards to remote GE interfaces, you can install GE SFP optical transceivers on the 10GE SFP+ interfaces. The best way is to check the bill of quotation (BOQ) before the deployment to avoid such interconnection. To determine whether interfaces on a 10GE interface card support SFP GE transceivers, see the "Indicators and Ports" section of the specific card. The following figures show the 16-port 10GE interface card and 12-port 10GE interface card for the S7700.
16-port 10GE interface card
12-port 10GE interface card