# Maximum length of packets using benchmark\_tx/rx and packet\_utils

**URL:** <https://www.ruby-forum.com/t/maximum-length-of-packets-using-benchmark-tx-rx-and-packet-utils/226992>\
**Category:** GNU Radio\
**Created:** [February 28, 2013, 2:03am UTC](https://www.ruby-forum.com/t/maximum-length-of-packets-using-benchmark-tx-rx-and-packet-utils/226992 "2013-02-28T02:03:58Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Chris\_Valenta](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@Chris\_Valenta](https://www.ruby-forum.com/u/Chris_Valenta)\
**Post date:** [February 28, 2013, 2:03am UTC](https://www.ruby-forum.com/t/maximum-length-of-packets-using-benchmark-tx-rx-and-packet-utils/226992/1 "2013-02-28T02:03:58Z")

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Hey all,  
I’m curious if there is a reason why the maximum length for a digital  
packet payload is 4096 bits in packet\_utils.py Currently this is limited  
because of the length of the whitening mask, but if whitening is not  
used…could this be increased? I know the framer\_sink limits the length  
of the total packet to 16 bits, but I’m using far less than this with no  
success.

I’ve tried disabling whitening and commenting out the packet length  
restriction of 4096 bits and put a larger packet through and it will  
transmit fine, but not receive a correct packet. The received packet is  
truncated as if all 16 bits in the framer\_sink d\_header\_len limit aren’t  
being used.  
Am I correct in this?

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**Author:** ![Chris\_Valenta](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@Chris\_Valenta](https://www.ruby-forum.com/u/Chris_Valenta)\
**Post date:** [February 28, 2013, 3:08pm UTC](https://www.ruby-forum.com/t/maximum-length-of-packets-using-benchmark-tx-rx-and-packet-utils/226992/2 "2013-02-28T15:08:06Z")

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On Wed, Feb 27, 2013 at 8:03 PM, Chris Valenta  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)wrote:

> restriction of 4096 bits and put a larger packet through and it will  
> transmit fine, but not receive a correct packet. The received packet is  
> truncated as if all 16 bits in the framer\_sink d\_header\_len limit aren’t  
> being used.
> 
> Am I correct in this?

Chris,

I would assume that you can extend the packet length as you are trying.  
But  
it’s possible that there is logic in the receiver that also expects  
packets  
to be 4096 or less because of this restriction in the transmitter. I  
honestly can’t remember off the top of my head.

But if you’ve removed the whitener, just remember that it’s there for a  
purpose to scramble the bits transmitted, so make sure you are  
transmitting  
random values to make the packets look white or you may run into issues  
with the synchronizers.

Tom