Converting Sites to MPLS

[newtonetworking221]

We have eight remote sites across the country.  They are currently all interconnected with VPN tunnels.  I'd like to convert these sites to an MPLS cloud.  I've applied for and received our own ASN through ARIN with a /24 public block.  I have a few questions about MPLS and how I can go about converting all of my sites.  I'd like to peer with the MPLS provider.  I'll be using BGP. Here are my questions:

1) Do I have to use the same MPLS provider across the country?  If I find a cost effective provider, that provider might not have a presence in some parts of the country.

2) If the answer to #1 is no, how do the providers communicate with each other to advertise my subnet? 

3) Using BGP, I do understand how to configure the protocol, and how to advertise my internal subnets through the provider network.  However, if I remote-as to different providers, will this be an issue? 

4) Are there any other considerations I need to take into account?

Again, I'm fairly new to networking.  Any help is very much appreciated!  Thank you in advance!

[e.ciollaro]

Hi

1) Do I have to use the same MPLS provider across the country?  If I find a cost effective provider, that provider might not have a presence in some parts of the country.

In my experience (but I live in a small country compared to US, I suppose you write from there) connection across country use the same ISP but I suppose that big country are different because of wide; probably they are much more similar to international networks. In these cases we connect customer sites in our country, we buy connection in  foreign country from international ISP to whom we are interconnected. In some case connection  is a plain IPv4 connection in some other case MPLS packets are exchanged. In any case this is complexity hidden to our costumers who  just experience  a layer 3 network between their sites

2) If the answer to #1 is no, how do the providers communicate with each other to advertise my subnet?

See #1

3) Using BGP, I do understand how to configure the protocol, and how to advertise my internal subnets through the provider network.  However, if I remote-as to different providers, will this be an issue?

Usually ISP's MPLS network has public AS and customer has private AS (at least in my experience); if so, be sure that non private AS is in use in different sites otherwise BGP suppose this is a loop and discard the routes. In this case as-override and/or allowas-in   can help but double check that no loop can occur. Moreover consider if site has some backdoor connection may be redistributing BGP into an IGP. In that case be careful because routing feedback can occur. 

4) Are there any other considerations I need to take into account?

Ask your ISP(s) to verify your design, probably they have skilled  netwrok engineer who can help you to check your architecture.

Bye,

enrico.

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[lvtquan1991]

Hi Newtonetworking221, 

Thanks for e.ciollaro's answer.

I just want to make more information.

1) Do I have to use the same MPLS provider across the country?  If I find a cost effective provider, that provider might not have a presence in some parts of the country.

You don't have to. However, I think you should take only one provider, (if possible) it make easy for management.

2) If the answer to #1 is no, how do the providers communicate with each other to advertise my subnet? 

Providers will have connection between them. I called NNI connection (or provider - provider connection). As my experience, They will use the BGP  per vrf to advertise subnet.