How is mpls te used on mpls networks

[carl_townshend]

Hi all

im currently doing the spcor course.

they talk about mpls te using ospf etc.

how is this used when we have bgp mpls vpn’s?

does mpls te just build the best path via igp to the loopbacks and then bgp just uses this path ?

how do they tie together ?

[MHM Cisco World]

it called MPLS TE 
the path is build based one label the IGP have no much work,
the TE header send to tail and tail reply with Label 
the tunnel header will use this label to forward traffic 

[carl_townshend]

Would you mind elaborating ? For example if I have a mpls network with 2 pe’s talking to each other over the backbone, how does mpls te work ? Is it only useful if you have multiple underlay paths to the other PE? And does it do the TE on the path between the PEs and just tweaks the route to the other PEs as the next hop ?

im a little confused, sorry

[MHM Cisco World]

NO at all
you are welcome 
I will prepare lab and show you how label use to decide the path of traffic. 
hope finish it tomorrow 

[davidoliver]

MPLS te is used on MPLS networks to provide traffic engineering capabilities. It allows for the creation of tunnels that can be used to route traffic around congestion or failure points in the network. MPLS te can also be used to shape traffic and to allocate resources in a more efficient manner. Overall, it provides greater flexibility and control over how traffic is routed across an MPLS network.

[David Ruess]

Hello,

I am also working on SPCOR. This book may help:

https://www.ciscopress.com/store/mpls-fundamentals-9781587051975

Chapter 8 is MPLS TE.

-David

[carl_townshend]

One of the other questions I have is, what exact traffic is the traffic engineering done on if we are using MP BGP between the PE's?

I see that MPLS TE needs OSPF/ISIS and the labs we have done have used autoroute to learn routes via the mpls tunnel.

In a normal ISP environment on the PE, what traffic would the MPLS TE be steering? would it just be picking the best route between the PE's not based on the customer BGP traffic, but just the BGP PE reachability?, so basically the IBGP peering between the PE's.

I want to know where the BGP routes come into it, as we can only use OSPF/ISIS for MPLS TE.

Cheers