[afnog] Juniper MX "timing support" = ?

[Kofi ANSA AKUFO]

Hi Frank

Many happy returns !!!

The "timing support" is an Ethernet Equipment Clock (EEC) implementatation
functionality in Juniper routers (e.g. as you may have noticed with the T
in the model names - MX5-T, MX10-T, MX40-T and MX80-T). Other vendors have
their own implementation.

Circuit switched and or circuit "emulated" networks (mobile radio access
technologies), require time synchronization and in some technologies such
as wireless (i.e. frequency division duplex FDD and time division duplex
TDD) the need for phase alignment and correct time.

SONET/SDH technologies are traditionally used to provide these applications
(e.g. mobile backhauling) due to native support for clocking.

In recent times the need to reduce costs (i.e and increase capacity) and to
improve flexibility has triggered the use of packet-based or switched
networks to support these applications (i.e mobile backhauling).

Now ethernet which is a packet switched technology do not carry clock
synchronization information natively. The notable extensions to support
synchronization in packet-based network technology - typically ethenet may
be as follows;

1. Synchronous Ethernet <http://en.wikipedia.org/wiki/Synchronous_Ethernet>
(ITU-T G.8261 and ITU-T G.8264) is a physical layer technology that
functions regardless of the network load and supports hop-by-hop frequency
transfer, where all interfaces on the trail must support Synchronous
Etherne. Refer to Juniper's Synchronous Ethernet Overview
<http://www.juniper.net/documentation/en_US/junos12.3/topics/concept/ethernet-synchronous-overview.html>
for more info

2.  Precision Time Protocol
<http://en.wikipedia.org/wiki/Precision_Time_Protocol>( IEEE 1588-2008)* - *See
more from Juniper's Precision Time Protocol Overview
<http://www.juniper.net/documentation/en_US/junos12.3/topics/concept/ptp-overview.html>
doc page

In short "timing support" functionality enables you to deliver
synchronization services that meet the requirements of the present-day
mobile network, as well as future Long Term Evolution (LTE)–based
infrastructures.

Hope it helps.

Cheers

K.

On 7 January 2015 at 09:49, Frank Habicht <geier at geier.ne.tz> wrote:

> Hi all,
>
> happy new year to all!
>
> Apparently my googl'ing abilities are insufficient, so let me ask you for
> help.
>
> The Juniper MX 80 router is available with and without "timing support".
> While the other "midrange" MX5 - MX40 are only _with_ timing support.
>  ... it appears from a (possibly outdated) document, which I found on the
>      streets ...   ;-)
>   (maybe that's wrong..?)
>
> While it seems to smell a bit like SDH, I'd appreciate more hints, pointers
> or confirmation about what the "timing support" means and does.
>
> Thanks,
> Frank
>
> _______________________________________________
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>
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