[Asterisk-Users] Re: Using a Dual WAN Load Balancing Device

[Noah Miller]

> We have a client that wants to bond 2 DSL circuits instead of getting
> a T-1 (or similar) at their office to run their VoIP traffic on.  We
> came across this Multihomed Gateway (MH200):
>
> http://www.cyberpathinc.com/mh200/details.htm
>
> Does anybody think this would work if installed at the client location
> handling NAT for 10 Cisco 7960's and connecting to our public asterisk
> server?
>
> My concern (as is others on this list in regards to load balancing) is
> what would happen if a call had to be directed out the other WAN port
> of the MH200 or if a call were to come in on 1 circuit and it runs out
> of bandwidth - how would the call be delivered to the second circuit.
> Or even if during a call, the inbound audio is fine (since DSL usually
> has more bandwidth on the download), but the outbound audio stream had
> to be pushed out the other WAN port.
>
> Hope that all makes sense (I almost confused myself! LOL)
>
> I am not holding my breath that this is a viable solution, but was
> just wondering your thoughts.

I had the displeasure of working with the now defunct iSurfJanus from 
Amplify Networks which is similar to the MH200.  I'm not sure the MH200 
is capable of doing what you want it to do.  I don't think it does 
"incoming load balancing".  The only ways I know of to host a machine 
behind two or more connections,  "incoming load balancing",  are 1) 
BGP, 2) Cisco HSRP, or with 3) DNS and extremely short TTL values.  
There may be some other ways, but these are the popular ones.  The 
multiple WAN devices capable of incoming load balancing like the F5 
BigIP, Fatpipe Products, Radware Linkproof, etc. all use special DNS 
entries to spread the incoming connections between WAN connections.

When I looked at the product specs of the MH200 it makes no mention of 
BGP, DNS, or anything else that might handle incoming connections.  In 
fact, it doesn't say anything about incoming connections at all.

To answer your question directly, I don't know how the other products 
work, but I could configure the iSurfJanus to respond to requests only 
on the same connection they came in on.  If the MH200 does handle 
incoming connections, you will probably need to ask the folks that make 
it if you can explicitly specify to respond to incoming request on the 
same WAN connection they came in on.