MPLS load balancing with P2P DS3s

Discussion in 'Cisco' started by rcsdrob, Mar 25, 2009.

  1. rcsdrob

    rcsdrob Guest

    We have three core sites that are each connected via point-to-point
    DS3s, (triangle design) using OSPF. We also have an MPLS DS3 using
    BGP going into each site as well. One site is completely VoIP and
    requires QoS treatment. We would like to load balance between the P2P
    and MPLS links at each site and allow for dynamic failover should a
    link or two fail. Is this possible? If so, how is it accomplished?
    My coworker is leaning toward GRE tunnels, but I would like other
    opinions and options before we dive headlong down this trail.

    Thanks,
    Rob
     
    rcsdrob, Mar 25, 2009
    #1
    1. Advertising

  2. rcsdrob wrote:
    > We have three core sites that are each connected via point-to-point
    > DS3s, (triangle design) using OSPF. We also have an MPLS DS3 using
    > BGP going into each site as well. One site is completely VoIP and
    > requires QoS treatment. We would like to load balance between the P2P
    > and MPLS links at each site and allow for dynamic failover should a
    > link or two fail. Is this possible? If so, how is it accomplished?
    > My coworker is leaning toward GRE tunnels, but I would like other
    > opinions and options before we dive headlong down this trail.


    Lets see if I can guess your current situation correctly -

    Your P2P links are preferred and MPLS is only used when both P2P links
    at particular site have failed. Your MPLS is regular L3 VPN and not any
    kind of L2TPv3/AToM/etc.
    Are both P2P and MPLS terminated on the same router?

    Regards,
    Andrey.
     
    Andrey Tarasov, Mar 25, 2009
    #2
    1. Advertising

  3. rcsdrob

    Rob Guest

    On Mar 25, 3:21 pm, Andrey Tarasov <> wrote:
    > rcsdrob wrote:
    > > We have three core sites that are each connected via point-to-point
    > > DS3s, (triangle design) using OSPF.  We also have an MPLS DS3 using
    > > BGP going into each site as well.  One site is completely VoIP and
    > > requires QoS treatment.  We would like to load balance between the P2P
    > > and MPLS links at each site and allow for dynamic failover should a
    > > link or two fail.  Is this possible?  If so, how is it accomplished?
    > > My coworker is leaning toward GRE tunnels, but I would like other
    > > opinions and options before we dive headlong down this trail.

    >
    > Lets see if I can guess your current situation correctly -
    >
    > Your P2P links are preferred and MPLS is only used when both P2P links
    > at particular site have failed. Your MPLS is regular L3 VPN and not any
    > kind of L2TPv3/AToM/etc.
    > Are both P2P and MPLS terminated on the same router?
    >
    > Regards,
    > Andrey.



    Andrey,

    Thanks for your response. You are correct, the P2P links are
    preferred and the MPLS links are primarily used for failover, except
    for one site that is the VoIP gateway for 30 remote offices. The MPLS
    links use L3 VPN access. The P2P and MPLS connections terminate on
    different routers at each of the sites.

    Thanks,
    Rob
     
    Rob, Mar 25, 2009
    #3
  4. Rob wrote:
    > On Mar 25, 3:21 pm, Andrey Tarasov <> wrote:
    >> rcsdrob wrote:
    >>> We have three core sites that are each connected via point-to-point
    >>> DS3s, (triangle design) using OSPF. We also have an MPLS DS3 using
    >>> BGP going into each site as well. One site is completely VoIP and
    >>> requires QoS treatment. We would like to load balance between the P2P
    >>> and MPLS links at each site and allow for dynamic failover should a
    >>> link or two fail. Is this possible? If so, how is it accomplished?
    >>> My coworker is leaning toward GRE tunnels, but I would like other
    >>> opinions and options before we dive headlong down this trail.


    >> Lets see if I can guess your current situation correctly -
    >> Your P2P links are preferred and MPLS is only used when both P2P links
    >> at particular site have failed. Your MPLS is regular L3 VPN and not any
    >> kind of L2TPv3/AToM/etc.
    >> Are both P2P and MPLS terminated on the same router?


    > Thanks for your response. You are correct, the P2P links are
    > preferred and the MPLS links are primarily used for failover, except
    > for one site that is the VoIP gateway for 30 remote offices. The MPLS
    > links use L3 VPN access. The P2P and MPLS connections terminate on
    > different routers at each of the sites.


    I see two pretty big issues with this setup and your goal -

    First one is the fact that links have different capacity. While you can
    get 45Mbps between pair of sites on P2P, MPLS DS3 is oversubscribed at
    each site and as minimum at one location also carries remote traffic
    (either VoIP only or with data). You can trick routers that it's equal
    cost multipath, but in reality sessions sent over MPLS will be at
    disadvantage.

    Second is different QoS policies - with MPLS one being quite inferior.
    Depends on what you do you may get different traffic behavior between
    P2P and MPLS.

    That being said, you may want to look into policy based routing. With
    PBR you can ship specific (ideally non-interactive) traffic over MPLS.

    Regards,
    Andrey.
     
    Andrey Tarasov, Mar 26, 2009
    #4
  5. rcsdrob

    Rob Guest

    On Mar 25, 10:17 pm, Andrey Tarasov <> wrote:
    > Rob wrote:
    > > On Mar 25, 3:21 pm, Andrey Tarasov <> wrote:
    > >> rcsdrob wrote:
    > >>> We have three core sites that are each connected via point-to-point
    > >>> DS3s, (triangle design) using OSPF.  We also have an MPLS DS3 using
    > >>> BGP going into each site as well.  One site is completely VoIP and
    > >>> requires QoS treatment.  We would like to load balance between the P2P
    > >>> and MPLS links at each site and allow for dynamic failover should a
    > >>> link or two fail.  Is this possible?  If so, how is it accomplished?
    > >>> My coworker is leaning toward GRE tunnels, but I would like other
    > >>> opinions and options before we dive headlong down this trail.
    > >> Lets see if I can guess your current situation correctly -
    > >> Your P2P links are preferred and MPLS is only used when both P2P links
    > >> at particular site have failed. Your MPLS is regular L3 VPN and not any
    > >> kind of L2TPv3/AToM/etc.
    > >> Are both P2P and MPLS terminated on the same router?

    > > Thanks for your response.  You are correct, the P2P links are
    > > preferred and the MPLS links are primarily used for failover, except
    > > for one site that is the VoIP gateway for 30 remote offices.  The MPLS
    > > links use L3 VPN access.  The P2P and MPLS connections terminate on
    > > different routers at each of the sites.

    >
    > I see two pretty big issues with this setup and your goal -
    >
    > First one is the fact that links have different capacity. While you can
    > get 45Mbps between pair of sites on P2P, MPLS DS3 is oversubscribed at
    > each site and as minimum at one location also carries remote traffic
    > (either VoIP only or with data). You can trick routers that it's equal
    > cost multipath, but in reality sessions sent over MPLS will be at
    > disadvantage.
    >
    > Second is different QoS policies - with MPLS one being quite inferior.
    > Depends on what you do you may get different traffic behavior between
    > P2P and MPLS.
    >
    > That being said, you may want to look into policy based routing. With
    > PBR you can ship specific (ideally non-interactive) traffic over MPLS.
    >
    > Regards,
    > Andrey.



    Andrey,
    Thank you for your suggestion. We have considered routing across the
    multiple links based on destination and type of traffic. We were
    hoping to make the most efficient use of the available bandwidth to
    all types of traffic, but it doesn't sound feasible with the disparate
    WAN links in use.

    Thanks,
    Rob
     
    Rob, Mar 26, 2009
    #5
  6. rcsdrob

    Stephen Guest

    On Thu, 26 Mar 2009 07:23:01 -0700 (PDT), Rob <>
    wrote:

    >On Mar 25, 10:17 pm, Andrey Tarasov <> wrote:
    >> Rob wrote:
    >> > On Mar 25, 3:21 pm, Andrey Tarasov <> wrote:
    >> >> rcsdrob wrote:
    >> >>> We have three core sites that are each connected via point-to-point
    >> >>> DS3s, (triangle design) using OSPF.  We also have an MPLS DS3 using
    >> >>> BGP going into each site as well.  One site is completely VoIP and
    >> >>> requires QoS treatment.  We would like to load balance between the P2P
    >> >>> and MPLS links at each site and allow for dynamic failover should a
    >> >>> link or two fail.  Is this possible?  If so, how is it accomplished?
    >> >>> My coworker is leaning toward GRE tunnels, but I would like other
    >> >>> opinions and options before we dive headlong down this trail.
    >> >> Lets see if I can guess your current situation correctly -
    >> >> Your P2P links are preferred and MPLS is only used when both P2P links
    >> >> at particular site have failed. Your MPLS is regular L3 VPN and not any
    >> >> kind of L2TPv3/AToM/etc.
    >> >> Are both P2P and MPLS terminated on the same router?
    >> > Thanks for your response.  You are correct, the P2P links are
    >> > preferred and the MPLS links are primarily used for failover, except
    >> > for one site that is the VoIP gateway for 30 remote offices.  The MPLS
    >> > links use L3 VPN access.  The P2P and MPLS connections terminate on
    >> > different routers at each of the sites.

    >>
    >> I see two pretty big issues with this setup and your goal -
    >>
    >> First one is the fact that links have different capacity. While you can
    >> get 45Mbps between pair of sites on P2P, MPLS DS3 is oversubscribed at
    >> each site and as minimum at one location also carries remote traffic
    >> (either VoIP only or with data). You can trick routers that it's equal
    >> cost multipath, but in reality sessions sent over MPLS will be at
    >> disadvantage.
    >>
    >> Second is different QoS policies - with MPLS one being quite inferior.
    >> Depends on what you do you may get different traffic behavior between
    >> P2P and MPLS.
    >>
    >> That being said, you may want to look into policy based routing. With
    >> PBR you can ship specific (ideally non-interactive) traffic over MPLS.
    >>
    >> Regards,
    >> Andrey.

    >
    >
    >Andrey,
    >Thank you for your suggestion. We have considered routing across the
    >multiple links based on destination and type of traffic. We were
    >hoping to make the most efficient use of the available bandwidth to
    >all types of traffic, but it doesn't sound feasible with the disparate
    >WAN links in use.
    >

    1 issue may be that routes leaked through MPLS are going to be
    classified as OSPF external, and OSPF will prefer the internal routes.

    What sometimes makes sense is to choose the route depending on
    subsections of the address space - eg if subnet x/24 is at the remote
    site, advertise x/25 via BGP as well as x/24

    That way 50% of the target addresses prefer BGP when both routes are
    up.

    You can then tweak the routing to load balance by destination subnet -
    it wont be as efficient as letting the router do session based
    balancing.
    But you can get some extra capacity out of your multiple paths at the
    cost of manually sorting out the split in load.

    >Thanks,
    >Rob

    --
    Regards

    - replace xyz with ntl
     
    Stephen, Mar 26, 2009
    #6
  7. rcsdrob

    Rob Guest

    On Mar 26, 4:04 pm, Stephen <> wrote:
    > On Thu, 26 Mar 2009 07:23:01 -0700 (PDT), Rob <>
    > wrote:
    >
    >
    >
    > >On Mar 25, 10:17 pm, Andrey Tarasov <> wrote:
    > >> Rob wrote:
    > >> > On Mar 25, 3:21 pm, Andrey Tarasov <> wrote:
    > >> >> rcsdrob wrote:
    > >> >>> We have three core sites that are each connected via point-to-point
    > >> >>> DS3s, (triangle design) using OSPF.  We also have an MPLS DS3 using
    > >> >>> BGP going into each site as well.  One site is completely VoIP and
    > >> >>> requires QoS treatment.  We would like to load balance between the P2P
    > >> >>> and MPLS links at each site and allow for dynamic failover should a
    > >> >>> link or two fail.  Is this possible?  If so, how is it accomplished?
    > >> >>> My coworker is leaning toward GRE tunnels, but I would like other
    > >> >>> opinions and options before we dive headlong down this trail.
    > >> >> Lets see if I can guess your current situation correctly -
    > >> >> Your P2P links are preferred and MPLS is only used when both P2P links
    > >> >> at particular site have failed. Your MPLS is regular L3 VPN and not any
    > >> >> kind of L2TPv3/AToM/etc.
    > >> >> Are both P2P and MPLS terminated on the same router?
    > >> > Thanks for your response.  You are correct, the P2P links are
    > >> > preferred and the MPLS links are primarily used for failover, except
    > >> > for one site that is the VoIP gateway for 30 remote offices.  The MPLS
    > >> > links use L3 VPN access.  The P2P and MPLS connections terminate on
    > >> > different routers at each of the sites.

    >
    > >> I see two pretty big issues with this setup and your goal -

    >
    > >> First one is the fact that links have different capacity. While you can
    > >> get 45Mbps between pair of sites on P2P, MPLS DS3 is oversubscribed at
    > >> each site and as minimum at one location also carries remote traffic
    > >> (either VoIP only or with data). You can trick routers that it's equal
    > >> cost multipath, but in reality sessions sent over MPLS will be at
    > >> disadvantage.

    >
    > >> Second is different QoS policies - with MPLS one being quite inferior.
    > >> Depends on what you do you may get different traffic behavior between
    > >> P2P and MPLS.

    >
    > >> That being said, you may want to look into policy based routing. With
    > >> PBR you can ship specific (ideally non-interactive) traffic over MPLS.

    >
    > >> Regards,
    > >> Andrey.

    >
    > >Andrey,
    > >Thank you for your suggestion. We have considered routing across the
    > >multiple links based on destination and type of traffic. We were
    > >hoping to make the most efficient use of the available bandwidth to
    > >all types of traffic, but it doesn't sound feasible with the disparate
    > >WAN links in use.

    >
    > 1 issue may be that routes leaked through MPLS are going to be
    > classified as OSPF external, and OSPF will prefer the internal routes.
    >
    > What sometimes makes sense is to choose the route depending on
    > subsections of the address space - eg if subnet x/24 is at the remote
    > site, advertise x/25 via BGP as well as x/24
    >
    > That way 50% of the target addresses prefer BGP when both routes are
    > up.
    >
    > You can then tweak the routing to load balance by destination subnet -
    > it wont be as efficient as letting the router do session based
    > balancing.
    > But you can get some extra capacity out of your multiple paths at the
    > cost of manually sorting out the split in load.
    >
    > >Thanks,
    > >Rob

    >
    > --
    > Regards
    >
    > - replace xyz with ntl


    Stephen,

    Thanks for your advice. We will take this into consideration as well.

    Thanks,
    Rob
     
    Rob, Mar 27, 2009
    #7
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Herbert Haas
    Replies:
    0
    Views:
    659
    Herbert Haas
    Jan 9, 2004
  2. Jimmi
    Replies:
    0
    Views:
    938
    Jimmi
    Aug 16, 2005
  3. Replies:
    1
    Views:
    2,403
    Vincent C Jones
    Nov 21, 2005
  4. ttripp
    Replies:
    4
    Views:
    3,797
    Ranak
    Nov 12, 2007
  5. palas_123
    Replies:
    1
    Views:
    2,194
    donjohnston
    Dec 28, 2009
Loading...

Share This Page