# Frame size ????

**URL:** https://community.cambiumnetworks.com/t/frame-size/42433
**Category:** ePMP
**Created:** [November 2, 2015, 11:32pm UTC](https://community.cambiumnetworks.com/t/frame-size/42433 "2015-11-02T23:32:49Z")
**Posts on this page:** 6
**Page:** 1

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### Author: ![toto](https://d10gw3vjmzyp8.cloudfront.net/letter_avatar_proxy/v4/letter/t/9f8e36/32.png) [@toto](https://community.cambiumnetworks.com/u/toto)
#### Post date: [November 2, 2015, 11:32pm UTC](https://community.cambiumnetworks.com/t/frame-size/42433/1 "2015-11-02T23:32:49Z")

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Hello everyone, someone could explain how and 'the Frame size configuration EPTP Master and Slave?

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### Author: ![Eric\_Ozrelic](https://d10gw3vjmzyp8.cloudfront.net/user_avatar/community.cambiumnetworks.com/eric_ozrelic/32/16188_2.png) [@Eric\_Ozrelic](https://community.cambiumnetworks.com/u/Eric_Ozrelic)
#### Post date: [November 2, 2015, 11:41pm UTC](https://community.cambiumnetworks.com/t/frame-size/42433/2 "2015-11-02T23:41:16Z")

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In both ePMP and PMP450 AP/master radios you can choose between 2.5ms frames and 5ms frames. By using 2.5ms frames your latency will be approx. half that of 5ms frames at the expense of a small percentage of overall bandwidth (maybe 10% or less). The reverse is true when using 5ms frames.

In addition, there are some GPS sync/collocation benefits to using either frame size.

In ePMP systems, you can use the 2.5ms frame time to collocate with PMP100 systems.

In PMP450 systems, you can use the 5ms frame time to collocate with PMP320/802.16e WiMAX radios.

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### Author: ![Dmitry\_Moiseev](https://d10gw3vjmzyp8.cloudfront.net/user_avatar/community.cambiumnetworks.com/dmitry_moiseev/32/12076_2.png) [@Dmitry\_Moiseev](https://community.cambiumnetworks.com/u/Dmitry_Moiseev)
#### Post date: [November 3, 2015, 2:51pm UTC](https://community.cambiumnetworks.com/t/frame-size/42433/3 "2015-11-03T14:51:42Z")

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Hi,

ePTP mode doesn't use fixed frame size. Fixed frame size is used and effects only for TDD fixed ratio modes.

2.5ms gives you lower latency and colocation with PMP100(aka Canopy), 5ms frame size gives you higher throughput.

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<div class="post-metadata">

### Author: ![toto](https://d10gw3vjmzyp8.cloudfront.net/letter_avatar_proxy/v4/letter/t/9f8e36/32.png) [@toto](https://community.cambiumnetworks.com/u/toto)
#### Post date: [November 3, 2015, 6:19pm UTC](https://community.cambiumnetworks.com/t/frame-size/42433/4 "2015-11-03T18:19:42Z")

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in the configuration master and slave I do not see adjustment Frame size, I just understand the system which is used in this configuration. 2.5 or 5?

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### Author: ![Dmitry\_Moiseev](https://d10gw3vjmzyp8.cloudfront.net/user_avatar/community.cambiumnetworks.com/dmitry_moiseev/32/12076_2.png) [@Dmitry\_Moiseev](https://community.cambiumnetworks.com/u/Dmitry_Moiseev)
#### Post date: [November 3, 2015, 6:21pm UTC](https://community.cambiumnetworks.com/t/frame-size/42433/5 "2015-11-03T18:21:38Z")

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Frame size is not used in ePTP mode, it is only used in TDD mode. This is why you don't see it. If you switch in TDD you can change it.

In ePTP mode system is automatically chaning frame size.

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### Author: ![jluthman](https://d10gw3vjmzyp8.cloudfront.net/letter_avatar_proxy/v4/letter/j/df705f/32.png) [@jluthman](https://community.cambiumnetworks.com/u/jluthman)
#### Post date: [November 4, 2015, 2:12am UTC](https://community.cambiumnetworks.com/t/frame-size/42433/6 "2015-11-04T02:12:46Z")

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I think what you want is TDD PTP mode. &nbsp;Which is really just TDD mode limited to one station and greater EIRP (for today's FCC rules).