Re: draft-dong-6man-enhanced-vpn-vtn-id-01

Looking at the draft, and reading your note, you seem to be asking for a 
hop-by-hop option header which is to be modify the forwarding selection 
in some unspecified fashion.

This kind of open-ended modification of core 6man IPv6 behavior seems a 
bad idea.
Having a modification to the forwarding behavior that may not be noticed 
or acted on by all routers in the path seems a recipe for forwarding loops.

And it is not at all clear that there is any need for this given MPLS, 
SRH, CRH.

Yours,
Joel

On 7/31/2020 4:47 AM, Dongjie (Jimmy) wrote:
> Hi Joel,
> 
> As explained in my previous mail, the role of DSCP and VTN-ID are different. VTN-ID can be used as a in packet identifier of the VTN, and it can be used in a hierarchical manner with DSCP and other fields for packet forwarding. Thus it is not to extend or replace DSCP.
> 
> Best regards,
> Jie
> 
>> -----Original Message-----
>> From: Joel M. Halpern [mailto:jmh@joelhalpern.com]
>> Sent: Wednesday, July 29, 2020 9:40 PM
>> To: Dongjie (Jimmy) <jie.dong@huawei.com>; 6man@ietf.org
>> Subject: Re: draft-dong-6man-enhanced-vpn-vtn-id-01
>>
>> It is unclear to me whether you are asserting that DSCP is insufficiently
>> granular to represent the desired treatment, or whether youa re asking for
>> an in-packet identifier that does not affect packet queueing or forwarding?
>>
>> Yours,
>> Joel
>>
>> On 7/29/2020 3:43 AM, Dongjie (Jimmy) wrote:
>>> Hi Ron,
>>>
>>> Thanks for your review and comment.
>>>
>>> Your interpretation is in the right direction, while the relationship
>>> between VTN-ID and DSCP could be considered as in a hierarchical
>>> manner, and each is for different purpose. VTN-ID is used to
>>> consistently identify a virtual network with a group of network
>>> resources allocated from the network, there is no priority difference
>>> between VTNs. DSCP is used to provide class (priority) based traffic
>>> differentiation, which can be used within VTN.
>>>
>>> Hope this helps.
>>>
>>> Best regards,
>>>
>>> Jie
>>>
>>> *From:*ipv6 [mailto:ipv6-bounces@ietf.org] *On Behalf Of *Ron Bonica
>>> *Sent:* Wednesday, July 29, 2020 1:45 AM
>>> *To:* 6man@ietf.org
>>> *Subject:* draft-dong-6man-enhanced-vpn-vtn-id-01
>>>
>>> Co-authors,
>>>
>>> In Section 4.2, you say:
>>>
>>> "There can be different implementations of reserving local network
>>>
>>>      resources to the VTNs.  On each interface, the resources allocated
>>> to
>>>
>>>      a particular VTN can be seen as a virtual sub-interface with
>>>
>>>      dedicated bandwidth and other associated resources.  In packet
>>>
>>>      forwarding, the IPv6 destination address of the received packet is
>>>
>>>      used to identify the next-hop and the outgoing interface, and the
>>> VTN
>>>
>>>      ID is used to further identify the virtual sub-interface which is
>>>
>>>      associated with the VTN on the outgoing interface."
>>>
>>> I interpret this as meaning:
>>>
>>> -The IPv6 destination address is solely responsible for identifying
>>> the IP next hop
>>>
>>> -The VTNI, along with the DSCP bits, determine how the packet is
>>> forwarded to the next-hop
>>>
>>> So, I can think of the VTNI as "more DSCP bits".
>>>
>>> Do I have that right?
>>>
>>>
>>                 Ron
>>>
>>> Juniper Business Use Only
>>>
>>>
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