[asterisk-dev] Asterisk scalability

[John Todd]

On Feb 19, 2009, at 7:24 PM, Watkins, Bradley wrote:

>
>
>> -----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



I'd be expecting all of those packets to come from a single MAC  
address, actually.

Hypothetical: My big router receives a 10gpbs ethernet from "the  
Internet".  Then, that router has three 1gbps interfaces that feed  
into my Asterisk box (which has three NICs.)  Thus, all of the traffic  
appears to come from the MAC address on the distant side of the 10gbps  
link.  I could generate the traffic from a zillion different  
endpoints, so hopefully UDP port hashing would work.  Would this work  
appropriately for spreading load on 802.3ad?

JT

---
John Todd                       email:jtodd at digium.com
Digium, Inc. | Asterisk Open Source Community Director
445 Jan Davis Drive NW -  Huntsville AL 35806  -   USA
direct: +1-256-428-6083         http://www.digium.com/