Subject: [nvo3] NVO3 Arch: Proposed text on VLANs in L2 Service

From: Thomas Narten <[email-masked]>
Date: Mon, 03 Feb 2014 14:57:54 -0500

Hi.

Here is proposed text on the topic of VLANs in L2 Service.

For terminology section:

	  <t hangText="VLAN">
	    Unless stated otherwise, the terms VLAN and VLAN Tag are
	    used in this document denote a C-VLAN and the terms are
	    used interchangably to improve readability.
	  </t>

Note; Following goes as a subsection withink 3.1  (at end of section)

<section anchor="vlan-tags-section" title="VLAN Tags in L2 Service">
    <t>
      An NVO3 L2 virtual network service can carry L2 VLAN tags
      provided by a Tenant System, but does not use them in deciding
      where and how to forward traffic. Such VLAN tags can be passed
      through, so that Tenant Systems that send or expect to receive
      them can be supported as appropriate. 
    </t>
    <t>
      The processing of VLAN tags that an NVE receives from a TS is
      controlled by settings associated with the VAP. Just as in the
      case with ports on Ethernet switches, a number of settings could
      be imagined. For example, C-TAGs can be passed through
      transparently, they could always be stripped upon receipt from a
      Tenant System, they could be compared against a list of
      explicitely confiured tags, etc.
    </t>
    <t>
      Note that the handling of C-VIDs has additional complications,
      as described in <xref target="vlan-tags-split-nve"/>  below.
    </t>
</section>

Note: the following goes as a new subection 4.2.1 (subsection of
Split-NVE)

<section anchor="vlan-tags-split-nve" title="Tenant VLAN handling in Split-NVE Case">
  <t>
    Preserving tenant VLAN tags across a NVO3 as described in
    <xref target="vlan-tags-section"/> poses additional complications
    in the split-NVE case. The portion of the NVE that performs the
    encapsulation function needs access to the specific VLAN tags that
    the Tenant System is using in order to include them in the
    encapsulated packet. When an NVE is implemented entirely within
    the hypervisor, the NVE has access to the complete original packet
    (including any VLAN tags) sent by the tenant. In the split-NVE
    case, however, the VLAN tag used between the hypervisor and
    offloaded portions of the NVE normally only identify the specific
    VN that traffic belongs. In order to allow a tenant to preserve
    VLAN information in the split-NVE case, additional mechanisms
    would be needed. 
      </t>
</section>

Comments?

Thomas

---

From: David Allan I <[email-masked]>
Date: Tue, 4 Feb 2014 01:05:12 +0000

Minor nit/suggestion

In the first paragraph would c/can carry/may include encapsulated/ be clearer?

And in that vein, I think in the subsequent text we are referring to the notion that the NVO3 network does not use encapsulated tags in deciding how to forward traffic. Prior to encapsulation they do matter, but indirectly, as that is on ingress to the NVE. So the subsequent text should be " but does not use encapsulated tags in deciding  where and how to forward traffic."

Make sense?
Dave

-----Original Message-----
From: nvo3 [mailto:[email-masked]] On Behalf Of Thomas Narten
Sent: Monday, February 03, 2014 11:58 AM
To: [email-masked]
Subject: [nvo3] NVO3 Arch: Proposed text on VLANs in L2 Service

Hi.

For terminology section:

	  <t hangText="VLAN">

Comments?

Thomas

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---

From: Thomas Narten <[email-masked]>
Date: Tue, 04 Feb 2014 08:55:18 -0500

Hi Dave.

Your changes look like useful clarifications and I've applied them to
my copy. Thanks!

Thomas

At Tue, 4 Feb 2014 01:05:12 +0000, David Allan I wrote:
> And in that vein, I think in the subsequent text we are referring to
> the notion that the NVO3 network does not use encapsulated tags in
> deciding how to forward traffic. Prior to encapsulation they do
> matter, but indirectly, as that is on ingress to the NVE. So the
> subsequent text should be " but does not use encapsulated tags in
> deciding where and how to forward traffic."
> 
> Make sense?  Dave
> 
> -----Original Message----- From: nvo3 [mailto:[email-masked]]
> On Behalf Of Thomas Narten Sent: Monday, February 03, 2014 11:58 AM
> To: [email-masked] Subject: [nvo3] NVO3 Arch: Proposed text on VLANs in
> L2 Service
> 
> Hi.
> 
>     </t> <t>
>     </t> <t>
>     Preserving tenant VLAN tags across a NVO3 as described in <xref
>     target="vlan-tags-section"/> poses additional complications in the
>     split-NVE case. The portion of the NVE that performs the
> _______________________________________________ nvo3 mailing list
> [email-masked] https://www.ietf.org/mailman/listinfo/nvo3
> _______________________________________________ nvo3 mailing list
> [email-masked] https://www.ietf.org/mailman/listinfo/nvo3
>

---

From: Jon Hudson <[email-masked]>
Date: Sun, 9 Feb 2014 15:44:07 -0800

Agreed! 

Thanks David!

> On Feb 4, 2014, at 5:55 AM, Thomas Narten <[email-masked]> wrote:
> 
> Hi Dave.
>