Bytes Received
Total bytes of RTP payload received by the endpoint — detect bandwidth throttling, asymmetric paths, and verify media delivery.
Bytes Received
| Property | Value |
|---|---|
| Key | bytes_received |
| Unit | Bytes |
| Type | Counter |
| Direction | Receive |
| RFC | RFC 3550 |
What It Measures
Bytes Received counts the total number of bytes of RTP payload data that arrived at the endpoint from the remote sender since the start of the media stream. It measures the actual volume of media data delivered to the receiver.
This is the reception counterpart to Bytes Sent. Comparing the two across endpoints reveals whether the network is delivering data symmetrically or if one direction is throttled or degraded.
Why It Matters
- Bandwidth throttling detection — If bytes received is consistently lower than what the sender reports transmitting, something in the network path is dropping or throttling traffic.
- Asymmetric path analysis — Comparing bytes sent and bytes received across both directions reveals if the upstream and downstream paths have different characteristics.
- Media delivery verification — The byte count confirms that the receiver is getting the expected volume of media data given the codec and call duration.
How CallMeter Measures It
CallMeter tracks the cumulative RTP payload bytes received at the endpoint. This counter is updated per second throughout the call.
Thresholds
This metric does not have fixed thresholds. Expected values should approximate the remote sender's bytes sent minus any bytes in lost packets.
Bytes Lost in Transit
If the remote endpoint sent 500 KB but the receiver only received 480 KB, the 20 KB difference represents the payload data in lost packets. You can cross-reference this with the Packets Lost count to verify consistency.
What Causes Unexpected Values
- Lower than expected — Packet loss in transit removes entire packets (and their bytes) from the received total. Also possible: bandwidth throttling by an intermediate device.
- Higher than bytes sent — Duplicate packets arriving via multiple network paths inflate the received byte count. Check Duplicate Packets.
- Stops incrementing — Remote endpoint stopped transmitting, or the network path is completely blocked.
How to Fix It
- Compare with sender. The ratio of bytes received to bytes sent gives you a byte-level delivery rate.
- Check for throttling. If delivery rate is below 95%, investigate QoS policies, rate limiters, and firewall rules on the network path.
- Verify with bitrate. The Receive Bitrate metric shows the per-second rate, which is easier to compare against known bandwidth limits.
Related Metrics
- Bytes Sent — Transmission counterpart for byte-level loss analysis
- Receive Bitrate — Bytes received expressed as a per-second bitrate
- Packets Received — Divide bytes by packets for average packet size
- Packets Lost — Lost packets account for the byte delivery gap