[Asterisk-Users] What business IP phone to use

[Paul]

I have seen some very expensive switches fail. Nice thing about lower
cost devices is that you can afford to have spares. If you stick to a
standard way of labeling and connecting wires you can use good open
source monitoring software to detect switch failure. If you allow people
to randomly connect to a bank of switches it is not so easy to quickly
find and remedy such problems.

The more expensive switches are good if you are going to take advantage
of the features they offer. I have recently seen situations like
employees installing things like camera and itunes software that caused
local network problems. Managed switches allowed immediate remote
disconnection of the workstations. At this customer site the fancy
switches are used for all workstations and some 3rd party
servers(security video system is a good example). However, the
customer-owned servers I installed are plugged into a $40 switch. Those
servers are properly managed so there is no need for the features found
in the more expensive switches.

David Ankers wrote:

>Aha, micro seconds in networking terms is normally written usecs or us
>(actually it's the greek letter mu as in ulaw) rather than ms which are
>milliseconds seconds - what had me puzzled was that it was stated that this
>could harm the voice path!
>
>  
>
>>The difference can also cause unnecessary delays and therefor echo in the
>>path. For example, procurve switches typically have 13ms switching time,
>>the high-end netgears about 21ms. As soon as you stack a couple of
>>switches you are talking 26ms vs 42ms extra delay in the path!
>>    
>>
>
>There is then only 8 usecs between the two switches, how on earth would this
>make any difference to the voice path at all? Let alone induce any echo... 
>
>Obviously the originally poster didn't understand the difference. And based
>on this, he's probably advising people not to use Netgear switches for
>voice, oh dear.  
>
>
>
>
>-----Original Message-----
>From: asterisk-users-bounces at lists.digium.com
>[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Watkins,
>Bradley
>Sent: Friday, 24 February 2006 10:08 PM
>To: 'Asterisk Users Mailing List - Non-Commercial Discussion'
>Subject: RE: [Asterisk-Users] What business IP phone to use
>
>It must be microseconds that is being quoted, as even the 2626 that you
>mention lists a less than 13.3 microsecond latency.
>
>- Brad
>
>-----Original Message-----
>From: asterisk-users-bounces at lists.digium.com
>[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of David Ankers
>Sent: Thursday, February 23, 2006 6:54 PM
>To: 'Asterisk Users Mailing List - Non-Commercial Discussion'
>Subject: RE: [Asterisk-Users] What business IP phone to use
>
>
>Are you sure those switch figures are right? 16ms delay in the switch path
>sounds a bit long. Cisco's mid-range switches like the 2950 have switching
>times measured in micro seconds. Then again a 2626 procurve is only around
>$700.
>
>
>-----Original Message-----
>From: asterisk-users-bounces at lists.digium.com
>[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Conrad Wood
>Sent: Friday, 24 February 2006 7:50 AM
>To: asterisk-users at lists.digium.com
>Subject: RE: [Asterisk-Users] What business IP phone to use
>
>
>  
>
>>Simple formula:
>>
>>1. Total Revenue
>>2. % of revenue derived from phone usage
>>3. =Cost of downtime by using SoHo or consumer gear.
>>
>>It's not a question of if a SoHo or low cost device will screw up, it 
>>is a question of when. This is 23 years of experience talking.
>>
>>Where I work, the value of #3 above is $16 Cdn a *second*. We are 
>>below
>>    
>>
>500
>  
>
>>employees, so we fall into the SMB segment. Sometimes I'm appalled by 
>>statements that a $700 switch or a $400 phone isn't worth it. Huh?? 
>>Maybe
>>    
>>
>in
>
>Absolutely right! for something as critical as switches & cabling I always
>recommend to spend real money. Don't ever try to save money any equipment
>that is required to operate the business. (Had very good experience with HP
>procurves over the last 10 years or so). There is no point buying netgear or
>other low-cost switches for a business ever. The cost saving of being able
>to pin-point a cabling/NIC/bandwidth problem down to the port on the switch
>easily and quickly is wonderful. Combined with SNMP and all the other
>goodies good switches come with, our clients save a lot of money by paying
>me less for my time ( d'oh ;-) ). The difference can also cause unnecessary
>delays and therefor echo in the path. For example, procurve switches
>typically have 13ms switching time, the high-end netgears about 21ms. As
>soon as you stack a couple of switches you are talking 26ms vs 42ms extra
>delay in the path!
>
>I see no reason however to spend $400 on a single phone though, because if a
>single phone breaks, it's not going to bring your business to a standstill,
>is it? (I guess unless you only have one in the first place ;-) )
>
>conrad
>  
>