# Bursty traffic - Under runs

**URL:** <https://www.ruby-forum.com/t/bursty-traffic-under-runs/234454>\
**Category:** GNU Radio\
**Created:** [March 5, 2015, 7:07pm UTC](https://www.ruby-forum.com/t/bursty-traffic-under-runs/234454 "2015-03-05T19:07:32Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [March 5, 2015, 7:07pm UTC](https://www.ruby-forum.com/t/bursty-traffic-under-runs/234454/1 "2015-03-05T19:07:32Z")

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Hello,

I have a flowgraph as below

Packet Framer custom message block–\>PDU to tagged stream --\>Modulation  
–\>Interpolation --\>HackRF(osmocom)

What I see is that when there is no packets to transmit HackRF reports  
underuns. This is going to be the case with any busty traffic. So how  
this should be handled?

Regards  
PP