Currently we have centrally located NAS/PPPoE servers (we have multiple) and it works well. I'm looking at pushing them further out into the network and using OSPF for the core/distribution layer of the network and using PPPoE to handle the access layer. That way it's just layer 2 from the AP to the customer, and routed layer 3 the rest of the way.

Makes it easy for failover and load balancing across links using a dynamic routing protocol like OSPF vs trying to bond or use other layer 2 protocols to accomplish the same thing.

• Have a decent monitoring platform and make sure it dials you PPPoE platforms to ensure its running
• Move your AAA to the core - this allows for effective billing and IP block allocations
• Make sure you plan your subnetting/IP allocations and use an intelligent Radius (AAA) to do this - allocate IPs from correct pools based on customer sites etc
• Think about inter-customer traffic - do you want to keep 'edge' customer away from your precious backhauls - do you plan to offer end-to-end VPNs for customers (and should this traverse your core
• Dynamic Routing protocols for the win - but try not to have too much flapping going on (more on this later)

• Appropriate during initial stages with a few sites or in situations where remote sites are possibly prone to vandalism or theft
• If limited field staff are available centralising makes is easier to fix/maintain
• If the backhaul is not your own you may have limited VLAN/MTU/privacy and want to encapsulate all traffic
• Inbound traffic that you wish to block (eg torrents) get stopped at the core - instead of pushing all the way down to the edge sites
• Two customers on same tower would have to backhaul all the way to the core to communicate - not ideal if that often happens
• Single point of failure - but you can build some decent resilliance/failover if you are decently monitoring and AAA

• Each individual site is self-contained meaning customer sessions terminate close to the customer
• Bandwidth management, QoS tagging etc can be done at the edge
• Inter customer traffic does not have to go to the core - depends on your routing architecture
• If a all backhauls fail the customer may be left with a connected system but no internet - script and redirect customers on failures
• Multiple internet breakouts can be effectively used
• A customer that sees multiple towers can fail over in case of a failure on one highsite

• Would recommend OSPF only for the connected backhaul links
• iBGP between sites internally
• Configure subnets/aggregates based on site locations to keep the entries required to a minimum
• Consider MPLS if you want to do backhaul hiding and some nice engineering
• Keep in mind that any tunnels you build adds overhead and potentially adversely affects performance

You could use a central based NAS and run MLPS on top of the OSPF network and tunnel the traffic back to the central NAS ...

I've seen a few posts of people doing this, I'm not sure what the impacts from added overhead are... but it's one way to have your cake and eat it too.

Also look into /32 routing (similar to Cisco's unnumbered interfaces)... I use those instead of /30's to eliminate wasted IP's for PTP links.

I've seen a few posts of people doing this, I'm not sure what the impacts from added overhead are... but it's one way to have your cake and eat it too.

Hope this provides some food for thought. Maybe a last link of relevance from one of my business partners regarding the value of PPP (TheRodent) - Open Access Networks, or “PPP” is not dead

You could use a central based NAS and run MLPS on top of the OSPF network and tunnel the traffic back to the central NAS ...

I've seen a few posts of people doing this, I'm not sure what the impacts from added overhead are... but it's one way to have your cake and eat it too.

Also look into /32 routing (similar to Cisco's unnumbered interfaces)... I use those instead of /30's to eliminate wasted IP's for PTP links.

Hello,

do you have the PPPoE server (NAS) at a central router in your NOC, or a small one to each tower? What are the pros and cos?
I think that is better to a central place, so you have 1 point for authenticate the user and do traffic logging.

The CONS are:
1) you have to encapsulate the traffic from each tower to the NOC on the PPPoE Tunnel, so QoS are more difficult.
2) you have to route much more big packet (EoIP or VPLS) to route L2 from each tower to NOC, because the pppoe works on L2

any other opinion?

Hello Guys,

Resurrecting this old thread....I'm looking to carry my pppoe with ibgp. Anyone who's tried this? How do you summarize the /32s? I suppose redistribute connected routes into bgp and route filter what you don't want bgp to advertise. But then how to supernet the many /32s? Any help very much appreciated.

Aye!
Dave.

ip route add type=blackhole dst-address=172.16.0.0/24

ip route add type=blackhole dst-address=172.16.0.0/24 bgp-communities=XXX:XXXXX

routing bgp network add network=172.16.0.0/24 synchronize=yes