RE: 40G reforming

["Ryan, Spencer" <sryan () arbor net>]

40G is either 4 x 10G over a single pair, or broken out into 8 fibers in the short or parallel versions.

Almost all Ethernet platforms support running most or all of their 40G ports as 1 x 40 or 4 x 10. 

When using the breakout cables though your options are usually more limited. A 1U switch as a 4 x SFP+ to 1 x QSFP(28) 
converter will work, depending on your use case. 


Spencer Ryan | Senior Systems Administrator | sryan () arbor net Arbor Networks | The security division of NETSCOUT
+1.734.794.5033 (d) | +1.734.846.2053 (m)
www.arbornetworks.com

-----Original Message-----
From: NANOG [mailto:nanog-bounces () nanog org] On Behalf Of Baldur Norddahl
Sent: Monday, February 5, 2018 10:57 AM
To: nanog () nanog org
Subject: 40G reforming

Hello

Is it possible to reform a 40G signal as individual 10G links?

The idea is to use a 40G QSFP multimode MTP module such as 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.fs.com_products_44058.html&d=DwICaQ&c=Hlvprqonr5LuCN9TN65xNw&r=Iw8ah1pcqZhOErIjaFRfuA&m=6Ncau5mGbJHTsn49WZBhiGcOVEmu482YmvfcECst4Mw&s=n2mTvNLQoiqsoG6Xi1BrMs_SjV3eJO4k15Bo0EUujAg&e=.
 Then connect it using a MTP breakout cable such as 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.fs.com_products_68049.html&d=DwICaQ&c=Hlvprqonr5LuCN9TN65xNw&r=Iw8ah1pcqZhOErIjaFRfuA&m=6Ncau5mGbJHTsn49WZBhiGcOVEmu482YmvfcECst4Mw&s=QQafQeEfacv-FvVFG7i3lwVhi_0mf3k9if5ROFPqpF0&e=
 to get four dual fiber connectors. These are then connected to four 10G SFP+ multimode modules such as 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.fs.com_products_11589.html&d=DwICaQ&c=Hlvprqonr5LuCN9TN65xNw&r=Iw8ah1pcqZhOErIjaFRfuA&m=6Ncau5mGbJHTsn49WZBhiGcOVEmu482YmvfcECst4Mw&s=kHc5CkRMpHo-GOihA9giouVj-Ua8mfpDWy8-PFEoi7U&e=.
 The reformer could be 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.fs.com_products_43721.html&d=DwICaQ&c=Hlvprqonr5LuCN9TN65xNw&r=Iw8ah1pcqZhOErIjaFRfuA&m=6Ncau5mGbJHTsn49WZBhiGcOVEmu482YmvfcECst4Mw&s=1ZjK8WS9SvmkSJZuO3ONs20yRL2BLAJTfdYxi-SCu9A&e=.
 And finally the reformed signal can be transported using anything including DWDM modules such as 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.fs.com_products_44058.html&d=DwICaQ&c=Hlvprqonr5LuCN9TN65xNw&r=Iw8ah1pcqZhOErIjaFRfuA&m=6Ncau5mGbJHTsn49WZBhiGcOVEmu482YmvfcECst4Mw&s=n2mTvNLQoiqsoG6Xi1BrMs_SjV3eJO4k15Bo0EUujAg&e=.

Just using fs.com as a reference to the kind of equipment I am talking about. Many other vendors offer simelar products.

The motivation for doing this is to get access to the many options that are available for 10G optics but not possible 
with 40G.

Regards,

Baldur