[asterisk-dev] Asterisk scalability

[Watkins, Bradley]

> -----Original Message-----
> From: asterisk-dev-bounces at lists.digium.com 
> [mailto:asterisk-dev-bounces at lists.digium.com] On Behalf Of John Todd
> Sent: Tuesday, February 17, 2009 5:31 PM
> To: Asterisk Developers Mailing List
> Subject: Re: [asterisk-dev] Asterisk scalability
> 
> 
> After some reading, I am unclear if Cisco devices work as 
> expected for  
> transmitting inbound load - I can't find any methods by which  
> something like "round-robin" can be specified on an 802.3ad group -  
> Linux how-tos are pretty clear how it can be done on the host side.   
> It seems that Cisco gear only supports failover capabilities. 
>  This, I  
> hope, is just my lack of time to search for better answers.  If you  
> know that Ciscos can semi-evenly transmit load across two or more  
> 802.3ad interfaces using some heuristic, let's hear about it.  Or  
> other network gear, for that matter.

Pretty much any network gear that I've worked with that supports
interface bonding, whether it be called EtherChannel (Cisco), MLT
(Nortel), 802.3ad (IEEE standard), or whatever, distributes frames based
on a hash of one or more of:  source MAC, destination MAC, source IP,
and destination IP.  IIRC, some Cisco hardware can also hash UDP or TCP
ports.  This also presents some possible problems with testing, since
you will need to ensure that whatever traffic generation you are using
is capable of having many source MACs or IPs (depending on what hash
algorithm is in use for a given switch).  It also, obviously, means that
any work in this direction will have a big caveat that if you don't a
large enough variety of endpoints you may not achieve adequate load
balancing.

- Brad