'Backup Auto Tunnels' are what you're after.
The way you've currently set it out would need 'mpls traffic-eng backup-path' on the protected links. However this is the static backup tunnel way and if you use 'dynamic' paths the LSP will ...
Traffic steering is actually the task that is beyond MPLS TE itself. TE tunnel just provides the path, and it's up to other protocols and techniques to steer actual traffic. The same is true for bandwidth reservation. TE just says "there are 300 mbps reserved", but nothing stops your client from sending more than that.
So, your options are policies, static ...
Do all TE routes work this way? Does the original LSP path (w/o TE) have to be only one hop away?
No the original LSP path can be multiple hops away.
MPLS TE is a very complicated subject, and I can hardly do justice to the nuances in a reasonable-sized answer. These are some of MPLS TE protection models for a primary LSP path along A -> B -> C ->...
As far as I know, in L3VPNs which are implemented on top of MPLS-TE
MPLS-TE and MPLS L3VPN are two independent features and L3VPN does not require the use of MPLS-TE. Some companies use MPLS-TE to achive specific routing or failover qualities for their L3VPNs, but MPLS-TE is only related to MPLS L3VPN by the fact that it uses MPLS labels.
Are there some ...
to expand on the previous answer -- policy is generally dictated by qos. an s/p will generally match on dscp or cos bits (cbts or pbts) to decide tunnel path.
there are other ways, in which you can match by source/destination addresses, vrf, etc. they usually take the form of some sort of access-list applied as a policy to the tunnel-path. the policy can ...
LSP is Predetermined path Over two Label edge Routers. It is established over Label switching router. It is based on Forwarding equivalence class. LSP is required to MPLS forwarding.
MPLS Traffic Engineering build unidirectional Tunnel between source and destination. IT is based on LSP Path.
For more details cisco
In todays routers routing lookup is done in hardware, usually in TCAM, which is as fast as ILM lookup.
So no advantage in lookup speed.
So why is it even needed? For tunneling.
If you want to deploy a full-mesh of tunnels dynamically between routers (usually PE routers) you can use LDP. This provides infrastructure for services like L3VPN, L2VPN etc.
Tunnel is a construct/container of following: source, destination, path/s.
It is the tunnel that is used by upper level application to resolve NH to destinations. e.g. L3-vpn, L2-vpn.
Source = Sender, destination = receiver, path = LSP.
Tunnel may have more that one path or LSP. Use-case of multiple path is primary/secondary
LSP may be signaled by control ...