Subject: Re: Re: Re: RE: draft-lasserre-vkompella-ppvpn-vpls as working group draft

From: Ali Sajassi <[email-masked]>
Date: Tue, 15 Apr 2003 16:40:08 -0700

>
> >1) Unqualified learning: all traffic from a given customer is tagged by
> >P-VLAN, so if a customer is connected to a given access network through 10
> >different ACs (and through several different MTU-s), then all those ACs
> >will be tagged by the same P-VLAN. The P-VLAN as mentioned before
> >corresponds to a single VPLS instance. Thus, all C-VLANs for a that
> >customer share the same MAC address domain and broadcast domain.
> >
> >2) Qualified learning: each C-VLAN is represented by a P-VLAN. Thus a given
> >C-VLAN (e.g., VLAN-10) over different ACs maps into a unique P-VLAN (e.g.,
> >VLAN-100) and that P-VLAN corresponds to a single VPLS instance.
> >
> >Therefore, in both cases, a single P-VLAN correspond to a single VPLS
> >instance and vise versa - e.g., one-to-one mapping.
> >
>
>No. You misunderstand my point. I'm not talking about learning, I'm 
>talking about value-add service, such as rate-limited, access list control.
>For learning,I agree with you, one P-VLAN to one VPLS-instance is enough. 
>But for value-add service, it is not enough, require many P-VLANs to one 
>VPLS-instance.

For unqualified learning, customer's VLANs are transparent to the SP. And 
as the matter of fact there is single MAC address domain and broadcast 
domain for all the VLAN of that customer. So what that means is the 
customer's MAC addresses need to be unique across all the VLANs or else 
unqualified learning would not work for that customer. So, given that all 
MAC addresses of a given customer are unique, then you can run ACL based on 
customer's MAC for that P-VLAN. If multi SLAs are needed for unqualified 
learning, then you simply copy the CoS bits of the inner tag to he outer 
tag and perform QoS on the P-VLAN tag.

The situation for qualified learning, should be clear since there is no 
outer-tag and P-VLAN is just a mapping of the C-VLAN.

If this is yet not clear to you, please clearly state the issue with an 
example.

-Ali

---

From: Du Wenhua <[email-masked]>
Date: Wed, 16 Apr 2003 06:58:13 +0800

Hi, Ali Sajassi

	See my comments.

　　　　　　　　Du Wenhua
　　　　　　　　[email-masked]
　　　　　　　　　　2003-04-16

At 15:44:00 2003-04-15, Ali Sajassi wrote:
>>At 06:12 AM 4/16/2003 +0800, Du Wenhua wrote:
>>Hi, Ali Sajassi
>>
>> >>In this draft, there are two way to treat C-VLAN in MTU-rs:
>> >>1)if C-VLAN are not used as service delimiter, add P-VLAN.
>> >>      In this way, the isssue is that if two C-VLAN map into same P-VLAN,
>> >> the PE-rs can only distinguish two customer by C-VLANs. But, the C-VLAN
>> >> is untrusted, is not service delimiter. It is wrong for PE-rs to apply
>> >> different value-add service for different C-VLANs.
>> >>     So it is better to map into different P-VLANs for differnent custom
>> >> if the PE-rs want to distinguish them.
>> >>2)if C-VLAN are used as service delimiter, translating C-VLAN to a P-VLAN
>> >>     In this way, the issue is that if two C-VLAN are tranlated to one
>> >> P-VLAN, the PE-rs will couldn't distinguish two customer.
>> >>      So it is better way to use different P-VLANs for different customers.
>> >
>> >I thought this has already been explained in the draft. If not it might
>> >have been lost during editing. I will double check on this.
>> >
>>OK. Hope to add it, thanks.
>>To PE-rs,  P-VLAN is just looked as a AC , not be look as PW.  Many ACs 
>>can be  map to one VPLS-instance. So, many P-VLAN can map to one 
>>VPLS-instance also, even if these P-VLANs in one physical port.
>>If the MTU just map each customer to each P-VLAN, it become a VPWS/VLL. 
>>MAC learning is removed in MTU.
>
>No, that's not correct. Lets go over it one more time.
>

No. You misunderstand my point. I'm not talking about learning, I'm talking about value-add service, such as rate-limited, access list control.
For learning,I agree with you, one P-VLAN to one VPLS-instance is enough. But for value-add service, it is not enough, require many P-VLANs to one VPLS-instance.

>> >Thanks,
>> >Ali