I'm dealing with performance issues with a VOIP phone system.
The VOIP service provider provides a dedicated internet connection for VOIP and the "PBX" is externally provided by the VSP.
Since the PBX is external, even internal extension-to-extension VOIP calls cause external traffic.
We provide a dedicated VOIP firewall in the form of an RV320 followed by cascaded SG300 switches - configured with a VOIP VLAN with QoS set up.
We provide a dedicated internet connection and firewall for site data - independent of VOIP traffic.
There are 3 sites, each one with separate internet connections, firewalls, etc.
The largest site has about 20 phones and 25 workstations.
The smallest site has about 6 phones and 10 workstations
The middle site has about 9 phones10 workstations.
Data traffic is modest.
I believe the VOIP system is working overall as intended so the "problems" are a matter of service quality I'd say.
Problems are intermittent and include:
- audio is heard at one end and not the other.
- a very loud "screeching noise" is heard at one end or the other and can be audible at one or both ends. This is reported to be rather high-pitched and not like loud TV white noise.
- some incoming calls don't arrive on site and go directly to voice mail.
Overall, it's reasonable to say: "while the system seems to "work", service is unacceptable".
Since the 3 sites are each independent of the other re: VOIP, if all sites behave similarly (re: problems) then one might conclude that the problems are likely "external" and with the VSP. Yet, the type of internet feed, the VOIP firewall model, the internal switch models are also common.
It may be that the largest site is more affected with problems than the smaller 2 sites. That's a little hard to say.
- We could hire an expert in VOIP problems and SG300 switch QoS to assess our switch configurations and related network architecture. But, going from *no* particular QoS settings to VOIP- favoring priority settings seems to have not had much effect if any.
- We could figure out a way to measure things in order to determine what part of the overall VOIP system is responsible for the problems (thus WHO?).
- We are willing to tackle internal problems but don't know now what more to do. It would be good to be able to to conclusively determine who needs to tackle the problems ( us or the VSP or both?).
- We have limited confidence in the VSP's ability or motivation to address these issues. Often, the suggestions from the VSP are that we should instrument this and that. This is, in part, understandable. But motivation seems low. Is that normal?
Any recommendations on any of this?