[c-nsp] Trunked VLANs over FTTC VDSL2

[Alistair C]

Hello,

Integrated devices such as the Cisco 887VA-M or Cisco 897 which are
"approved and certified for use with BT GEA/FTTC and compliant with
SIN498", do not appear to support q-in-q across the VDSL ethernet interface.

The configuration examples I have reviewed and limited testing carried out
thus far show VLAN 101 tagged on the VDSL ethernet interface as per the BT
SIN requirement but there is an inability to tunnel additional VLANS across
this interface/VLAN cleanly, which is a requirement for the service we
provide.

I have raised the issue with Cisco to see if there is a work around or
something obvious with regards to configuration that I am missing but this
has not turned up anything positive so far.

Anyone out there trunking multiple VLANs to a Cisco CPE over FTTC, in a
similar position?


Thanks.

[Tarko Tikan]

hey,

Post by Alistair C
Anyone out there trunking multiple VLANs to a Cisco CPE over FTTC, in a
similar position?

I'm actually testing this as we speak. Not with BT but it doesn't really
matter.

See below for the config that should theoretically work, in reality it
does not. The packets are correctly double tagged in LAN>VDSL direction
but in VDSL>LAN direction packets are lost after they reach Vlan100
interface (by looking at packet counters). This is probably because
Vlan100 interface is not really expecting packets with dot1Q ethertype.

I haven't opened the case with Cisco yet but I don't have high hopes.
Having dot1q-tunnel on this platform is most likely mistake.

Do you know any other devices/vendors that could theoretically do this?
I only know about RAD ETX-2i at this point.



interface Ethernet0
mtu 1600
no ip address
!
interface Ethernet0.100
encapsulation dot1Q 100
bridge-group 1
!
interface FastEthernet0
switchport access vlan 100
switchport mode dot1q-tunnel
no ip address
!
interface Vlan100
mtu 1600
no ip address
bridge-group 1
!
bridge 1 protocol ieee
!

[Alistair C]

Post by Tarko Tikan
I'm actually testing this as we speak. Not with BT but it doesn't really
matter.
See below for the config that should theoretically work, in reality it
does not. The packets are correctly double tagged in LAN>VDSL direction but
in VDSL>LAN direction packets are lost after they reach Vlan100 interface
(by looking at packet counters). This is probably because Vlan100 interface
is not really expecting packets with dot1Q ethertype.
I haven't opened the case with Cisco yet but I don't have high hopes.
Having dot1q-tunnel on this platform is most likely mistake.
Do you know any other devices/vendors that could theoretically do this? I
only know about RAD ETX-2i at this point.

Hi, thanks for the reply.

For my purposes I need to terminate the VLANs on the Cisco CPE, rather than
pass through, as such I have not looked at alternative equipment, other
than devices that can potentially serve as FTTC VDSL2 Modems, to sit in
front of a Cisco CPE.

It is disappointing that Cisco do not seem to have implemented q-in-q
support on the Ethernet0 interface, on the 887 or 897.

[Tarko Tikan]

hey,

Post by Alistair C
It is disappointing that Cisco do not seem to have implemented q-in-q
support on the Ethernet0 interface, on the 887 or 897.

At least the commands for specifying second dot1q are missing so it's
very clear the functionality is not there.

[James Bensley]

This is a live working 897 using QinQ over VDSL:


interface Ethernet0
no ip address
!
interface Ethernet0.400
encapsulation dot1Q 101 second-dot1q 400
ip vrf forwarding test
ip address 1.1.1.2 255.255.255.252
!
interface Ethernet0.401
encapsulation dot1Q 101 second-dot1q 401
ip vrf forwarding test-2
ip address 2.2.2.2 255.255.255.252


#show ver | i IOS
Cisco IOS Software, C800 Software (C800-UNIVERSALK9-M), Version
15.5(3)M, RELEASE SOFTWARE (fc1)

#show ver | i C897
Cisco C897VA-K9

#show license
Index 1 Feature: advipservices
Period left: Life time
License Type: Permanent
License State: Active, In Use
License Count: Non-Counted
License Priority: Medium


#show controllers VDSL 0 | i VDSL
Controller VDSL 0 is UP
Trained Mode: G.993.2 (VDSL2) Profile 17a


Cheers,
James.
_______________________________________________
cisco-nsp mailing list cisco-***@puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

[Alistair C]

Post by James Bensley
#show ver | i IOS
Cisco IOS Software, C800 Software (C800-UNIVERSALK9-M), Version
15.5(3)M, RELEASE SOFTWARE (fc1)

Beware this does not appear to work yet on the Cisco 887VA-M.

A Zhone VDSL2 router in bridge mode, running recent firmware provides
working VLAN trunking to other devices.

[Alistair Cockeram]

Post by Alistair C
Beware this does not appear to work yet on the Cisco 887VA-M.

To update, it does work on the 887VA-M. Remove any existing "encapsulation
dot1Q” command if a subinterface is already configured, or the
“second-dot1q” command is not available.