[ovs-dev] [PATCH 0/3] auto-attach: auto-attach: Add support for IETF Auto Attach standard (v2)

Keene, Carl (Carl) ckeene at avaya.com
Fri Nov 7 15:00:07 UTC 2014


Ben - thanks for your comments and assistance - let me try to provide an answer to the first question, Dennis Flynn will send answers to the other items later today and Paul Unbehagen ( Avaya Chief Architect ) may email additional clarity:

We are aware of LLDP use in OpenFlow controllers and recognize that any addition of LLDP and Auto Attach functionality to the Open Vswitch must not break LLDP functionality in OpenFlow controllers.   Our current Auto Attach submission which uses LLDP is disabled on all ports by default and therefore the vswitch with the submitted code does not interfere with or require any change to OpenFlow controller's use of LLDP.   

Auto Attach uses LLDP for fabric service creation in addition to neighbor discovery.  The primary reasons Avaya and WindRiver joined development to add the Auto Attach logic into the vswitch rather than adding the logic exclusively to a controller are:  
1) increased scalability as the number of Auto Attach clients running LLDP protocol grows - the scalability is needed to support massive and robust fabric service creation
2) support fabric service creation without a controller -  standalone operation of open vswitch with Auto attach client 
3) fast service discovery, migration, and failover detection can necessitate lower LLDP PDU transmit timer - related to  scalability and robustness

When the Auto Attach feature is enabled it is done on a port basis by a controller..  Operation on ports that do not have Auto Attach enabled is unaffected by the feature and will continue to interoperate with Openflow controllers use of LLDP with no changes.  Ports that do have the Auto Attach feature enabled by the controller are affected as follows:
1) Auto Attach LLDP PDU's discovery and fabric service mappings between the Auto Attach client and server occur automatically on the enabled ports 
2) The controllers use of LLDP for topology discovery on an auto attach enabled port is not necessary because this port is now fabric connected 

Paul Unbehagen from Avaya will present at the openvswitch conference on Nov 17 in Palo Alto and can additionally provide detail in person.

Hope this helps, Carl Keene - Avaya 

-----Original Message-----
From: Ben Pfaff [mailto:blp at nicira.com] 
Sent: Tuesday, November 04, 2014 7:19 PM
To: Ludovic Beliveau
Cc: dev at openvswitch.org; Keene, Carl (Carl)
Subject: Re: [ovs-dev] [PATCH 0/3] auto-attach: auto-attach: Add support for IETF Auto Attach standard (v2)

Thanks for v2.

I often hear of LLDP used in connection with OpenFlow controllers and switches.  Until now, Open vSwitch has had no built-in support for LLDP, although support could be implemented through an OpenFlow controller.  This patch series does start adding built-in LLDP support.  I am not sure how this will interact with what users are doing through OpenFlow already.  Do you have any thoughts?  I would know a little more, if the LLDP support were documented, but vswitch.xml in the final patch is incomplete: it does not document the new "lldp" column (or "enabled" or "authentication_key" or "mappings").

It seems to me that most of the lldp code added in the first patch is really quite separate from the OVS code and accessed through a narrow interface (ovs-lldp.[ch]).  I think maybe the library code should go into a subdirectory of lib, e.g. lib/lldp, with only ovs-lldp.[ch] inside lib/ directly.  (The existing sflow code is another good candidate for this.)

Some of the files in patches 2 and 3 see to have inconsistent indentation.  I think that they are using tabs to indent some lines and spaces to indent others.  Open vSwitch source files should be indented with spaces.



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