# Room.getStreamStats() - A useful hidden API
**URL:** https://discourse.lynckia.com/t/room-getstreamstats-a-useful-hidden-api/688
**Category:** Uncategorized
**Created:** [January 4, 2018, 6:20am UTC](https://discourse.lynckia.com/t/room-getstreamstats-a-useful-hidden-api/688 "2018-01-04T06:20:47Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@mkh](https://discourse.lynckia.com/u/mkh)
#### Post date: [January 4, 2018, 6:20am UTC](https://discourse.lynckia.com/t/room-getstreamstats-a-useful-hidden-api/688/1 "2018-01-04T06:20:47Z")
I was playing with `ErizoClient.Room.getStreamStats()` and found it very useful to provide users some interesting information about the stream status. But the API seems to be unofficial since there is no documentation for it. The current output is hard to read and needs to be parsed and filtered. Consider the following output:
```auto
{
'888581ec-5d51-4881-b007-4f04983935cf': {
0: {
erizoAudioMute: 0,
erizoVideoMute: 0,
},
2780458502: {
bandwidth: 825600,
bitrateCalculated: 176165,
clientHostType: 'host',
fractionLost: 0,
jitter: 11619,
keyFrames: 1,
packetsLost: 0,
sourceSsrc: 2780458502,
type: 'video',
},
qualityLayers: {
0: {
0: 68968,
1: 180976,
2: 226672,
},
maxActiveSpatialLayer: 0,
maxActiveTemporalLayer: 2,
},
total: {
bitrateCalculated: 176165,
paddingBitrate: 102048,
senderBitrateEstimation: 825600,
},
},
publisher: {
2780458502: {
PLI: 1,
bitrateCalculated: 226499,
bytesSent: 85942,
clientHostType: 'host',
erizoBandwidth: 796317,
keyFrames: 2,
packetsSent: 103,
type: 'video',
},
total: {
bitrateCalculated: 226499,
paddingBitrate: 0,
},
},
}
```
At the moment you need to traverse the entire object and examine the type of keys to reach the data you need. One idea is to add the `sourceSsrc` ( **2780458502** in this example) to the stream attributes so finding the key is much easier.
In the other hand some data are ambiguous to me like `bandwidth` vs `erizoBandwidth` vs `bitrateCalculated` or `packetsLost` vs `fractionLost` vs `jitter`. BTW what is `PLI`??
Also the output seems incomplete. For example we have `bytesSent` for the publisher but there is no `bytesReceived` for the subscriber which could be useful for calculating the total upload/download traffic usage.
---
### Author:  [@Francesco\_Durighetto](https://discourse.lynckia.com/u/Francesco_Durighetto)
#### Post date: [January 4, 2018, 4:09pm UTC](https://discourse.lynckia.com/t/room-getstreamstats-a-useful-hidden-api/688/2 "2018-01-04T16:09:54Z")
The PLI is the packet loss indicator.
Consider the following example:
You have a poor connection and, since the webrtc stream if not passing thru a special TURN is an UDP packets stream, your packets could be lost from your pc to the server.
So there’s a mechanism called NACK that starts to act.
The server send to you (client) a NACK request for the specific packet lost (he know that one packet is missing since they are ordered incrementally).
Your client has a small buffer of sent packet, so it resend the packet.
But this packet (if the loss rate is very high) could be lost again and again.
If you can’t retransmit this packet in a certain span of time, the server will request you a PLI, because your lost packet has interrupted the decoder and he can’t render no more since you send him a FULL picture called keyframe. A PLI is simple a keyframe request. you will always at least 1 PLI since it’s the first keyframe you send to server during the call initialization
---
### Author:  [@mkh](https://discourse.lynckia.com/u/mkh)
#### Post date: [January 5, 2018, 8:17am UTC](https://discourse.lynckia.com/t/room-getstreamstats-a-useful-hidden-api/688/3 "2018-01-05T08:17:09Z")
Thanks for the explanation!
Then what’s your suggestion for a simple and easy to understand report of the connection quality to the end user? I mean how to benefit from these values (e.g. pli, jitter, packet loss, etc) to provide a real time feedback report?
---
### Author:  [@Francesco\_Durighetto](https://discourse.lynckia.com/u/Francesco_Durighetto)
#### Post date: [January 5, 2018, 8:25am UTC](https://discourse.lynckia.com/t/room-getstreamstats-a-useful-hidden-api/688/4 "2018-01-05T08:25:56Z")
this is a good starting point!
[Callstats.io](https://www.callstats.io/2015/07/06/basics-webrtc-getstats-api/)
---
### Author:  [@mkh](https://discourse.lynckia.com/u/mkh)
#### Post date: [January 5, 2018, 9:40am UTC](https://discourse.lynckia.com/t/room-getstreamstats-a-useful-hidden-api/688/5 "2018-01-05T09:40:55Z")
Great article! Thanks.
---
### Author:  [@mkh](https://discourse.lynckia.com/u/mkh)
#### Post date: [January 25, 2018, 4:42am UTC](https://discourse.lynckia.com/t/room-getstreamstats-a-useful-hidden-api/688/6 "2018-01-25T04:42:07Z")
The problem with the API is that it reports stats of all subscribers. So with a large number of participants it’s unwise to be used in the browser and to fetch a large amount of data every moment. I think adding a new param to the API to fetch only stats of a specific subscriber would be useful.