[asterisk-users] switch QOS requirements

[Julio Arruda]

Al lists wrote:
> Theoretically, setting TOS value ( these days called DSCP) wont change
> anything in switch behavior, unless you are using Layer 3 switches.
> What makes a difference in a switch is COS bits, and i'm not sure how
> asterisk sets that.
> I guess to be safe, you would need to create 2 VLANS and in the switch
> define on VLAN  as a high priority VLAN.

At least for quite few years (more than 5), layer 2 switches from Nortel 
(disclaimer, I used to work for NT), would be able to match DSCP (or 
remark DSCP also, based in l3/l4 information) and give priority as 
defined by the user, to specific DSCP #, like EF to highest priority and 
goes on.
I've no reason to believe other vendors don't have at least this capability.

> On Feb 3, 2008 7:06 PM, Michael Graves <mgraves at mstvp.com> wrote:
> 
>> On Sun, 03 Feb 2008 22:11:04 +0100, Benny Amorsen wrote:
>>
>>> "John Williams" <jw.ip.pbx at gmail.com> writes:
>>>
>>>> We are tearing out legacy PBX and replacing with Asterisk PBX and new
>>>> LAN for our 90+ person operation.   Question:  what QOS capabilities
>>>> (protocols, etc) does Asterisk support/require in a LAN switch to
>> deliver
>>>> business grade phone service?  Thanks
>>> If you have one switch for the whole network, you're generally fine
>>> without QoS. Switches these days can handle full bandwidth on all
>>> ports at the same time.
>>>
>>> Anyway, Asterisk is no different from other PBX's when it comes to
>>> QoS. Should it turn out that you actually need it on the LAN, just be
>>> sure you set the tos parameters in sip.conf to something that is
>>> prioritized by the switch.
>> It tends to be more of an issue when you're sending calls over a link
>> with limited bandwidth. Usually more of a concern in the router.
>>
>> Michael
>> --
>> Michael Graves
>> mgraves<at>mstvp.com
>> blog.mgraves.org
>> o713-861-4005
>> c713-201-1262
>> sip:mjgraves at pixelpower.onsip.com
>> skype mjgraves
>> fwd 54245