[Note] I’ve recently started a network consultancy business, head over to Optimus Networks to get in touch.
I recently learned that the Cisco 887VA packs a dual technology modem that supports not only ADSL2+ but VDSL2, the technology that supports FTTC (Fibre To The Cabinet), more commonly known as BT Infinity.
Excited at the prospect of removing the Openreach modem from my over-heating cupboard / home comms room, I set about building the config and was surprised to find FTTC to be very similar in delivery to a Etherflow Etherway. The similarity being that the circuit is delivered with a vlan tag, that is 101. The authentication is done via CHAP/PPPOE, see my previous posts on how to get an Ethernet connection established from an Ethernet port on a router or an ASA.
There is no ATM configuration as per ADSL, the VDSL modem is tied to the Ethernet0 interface and must be bound to a dialer carrying the PPPOE configuration. Also, since the service arrives tagged, an Ethernet0.101 sub-interface must be configured and bound to the dialer.
Here is the config :
controller VDSL 0 !## TELL THE ROUTER WE WILL BE USING VDSL MODE
no ip address !## SEE THE DIALER
interface Ethernet0.101 !## EVERYTHING IS TAGGED IN VLAN 101, SO WE MUST USE A SUB INTERFACE
encapsulation dot1Q 101
pppoe-client dial-pool-number 1
interface ATM0 !## NO NEED FOR THIS
no ip address
no atm ilmi-keepalive
ip address negotiated
ip virtual-reassembly in
dialer pool 1
ppp authentication chap callin
ppp chap hostname YOUR_LOGIN
ppp chap password 0 YOUR_PASSWORD
ppp ipcp dns request
ppp ipcp route default !## GRAB YOUR 0.0.0.0/0 ROUTE FROM PPPOE
In-case of issues or slow performance, I believe the FTTC MSAN equipment will fall back to ADSL2+ mode if required so check you have specified VDSL mode as per the 1st line of the config if you have any trouble. Not that I’ve had any issues.
Also, in-case you are wondering what speed your line is capable of, since BT recently announced 80Mbps downstream for new or renewing customers, the VDSL stats show a good amount of detail including a headline reading for your line. I was pleasantly surprised..
Router#sh controllers VDSL 0
Attainable Rate: 102056 kbits/s 33192 kbits/s
According to these numbers I’ve lost a whole 2Mbps downstream, a previous reading showed 104Mbps. I wonder if the nice weather we’ve had this week had an effect on the cable? Damn you physics! 😉