IN one IGW firm in bangaldesh have 3 uplink on two NE40 Routers with the version of V3R5. the link descriptions is below.
they are incoming load balanced through BGP. but the problem is the BGP ougoing load balance.
As i imported max routes from 3 upstream ,at peak time singtel outgoing interface is reached to its maximum bandwidth,as a matter of fact,
the carriers who are using this link for outgoing are facing call dropping prolems, but at that time TM and Epsilon have free bandwidth(20-40Mbps)
at there outgoing interface.so customer wants me to solve this outgoing imbalance problem.
i asked customer to give me the total VOIP carrier list. they provide me about 200 hundrad IPs where they want to send Voice traffic.
normally in BGP we dont know which destinstion customer will try to communicate as millions of website in Internet. but in IGW we have one advantages, that is
we know the destination of customer(200 IPs n this regrad).
in this case i have segregatted those IP to 3 class.
class A: TM outgoing
Class B:singtel Outgoing
Class c: Epsilon outgoing.
Example: customer wants the outgoing of xx.2xx.1xx.1xx this IP through TM.
as i use IP-prefix for importong traffic from uplink, i need to know which network segment this IP belongs to.
i have using some BGP looking glass software like route-views.oregon.ix-net and execute the command
sh ip route 2xx.2xx.1xx.1xx, i got the output 2xx.2xx.1xx.1xx/xx.
thats means this network belongs to 2xx.2xx.1xx.1xx/20 network.
so i have confogured my IP prefix to TM like below
ip ip-prefix TM-in index 20 permit 2xx.2xx.1xx.1xx
so now this routes is import from TM and all outgoing traffic destined to this carriers are going through TM.
before that it was going through singtel,as singtel was least hop towards this destination previously.
see the attachment for topology abd carrier list.
by this way we import 200 IPs from the 3 uplink based on customer requirements, which carries they want to reach through which link.
i solved customer requiremen by this way.
we can use these techniques for all IGW firms where destination is known.this is the best solution for IGW regarding outgoing load balance through BGP.