# Vsi concept in mpls
**URL:** https://forum.networklessons.com/t/vsi-concept-in-mpls/16970
**Category:** MPLS
**Created:** [January 29, 2022, 8:48am UTC](https://forum.networklessons.com/t/vsi-concept-in-mpls/16970 "2022-01-29T08:48:02Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@usmanakramz](https://forum.networklessons.com/u/usmanakramz)
#### Post date: [January 29, 2022, 8:48am UTC](https://forum.networklessons.com/t/vsi-concept-in-mpls/16970/1 "2022-01-29T08:48:03Z")
Hi ,
I need help in understanding vsi concept in mpls. Please assist.
Thanks
Ussie
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### Author:  [@lagapidis](https://forum.networklessons.com/u/lagapidis)
#### Post date: [February 1, 2022, 3:43pm UTC](https://forum.networklessons.com/t/vsi-concept-in-mpls/16970/2 "2022-02-01T15:43:00Z")
Hello Usman
There are several concepts by different vendors that use the abbreviation VSI. When it comes to Cisco, this is a Virtual Switch Interface. It was used with the old BPX multiservice switches. These are over 20 years old, so you’re probably not talking about this. But because I found it interesting, I decided to upload a datasheet from 1999 for the BPX 8600:
[technicheskie-kharakteristiki-kommutatori-cisco-bpx-8600-series-multiservice-switches.pdf](https://forum.networklessons.com/uploads/short-url/zgOv9tb7k5tOTze49jSySgsvvEs.pdf) (329.6 KB)
Virtual Switch Interface Protocol was used with these switches for MPLS, and you can find out more about that here.
> **[Virtual Switch Interface](https://www.cisco.com/c/en/us/td/docs/switches/wan/mgx/ses/software/ses_pnni_controller/configuration/guide/oricgapd.html)**
>
> Virtual Switch Interface
However, I believe you are talking about the VSIs used in H3C routers or Huawei devices.
Can you clarify what particular feature you are looking to learn more about?
I hope this has been helpful!
Laz