Prepare your Network for VoIP

The following is a general guide with our recommendations and best practices for a VoIP deployment. Prior to installation, it’s very important that the site is ready and optimized for VoIP service.

Cabling

Cat5/6 for each SIP device
Properly labeled RJ45 jacks for each SIP device
RJ11 jacks and cabling identified/available for fax/analog devices if using an ATA located in the network closet
Location selected for DECT base station, including cable run if not in-network closet
Appropriate copper pairs for use with paging system adapter run between amplifier and network closet/paging adapter location

ISP Modem

Call the ISP (or log in) to change your modem to "Bridge Mode" (Most ISPs) or "IP Passthrough" (AT&T)
This is VERY important if you have a router connected to your ISP modem. Without this you will have "double NAT", which will cause delays in voice and connection issues.
Not necessary if your ISP device is the only device you are using and it includes router and/or WiFi functions

Network Equipment

Enterprise platforms are preferred, with configuration and deployment by qualified network technicians. The following SMB routers have the capabilities to run basic QoS and may provide better voice quality.

Factors to keep in mind when selecting network equipment:

PoE switch with enough ports available for SIP devices
If you don't have Power Over Ethernet, make sure you order power cubes for phones (they don't come with power cubes).
Cable runs patched into the switch and tested
UPS for equipment including SIP devices located in network closet (paging, ATAs, etc)

Network Configuration

Voice VLAN created
QoS policy built and tested to give voice highest priority
Disable SIP ALG
Throttling and policing strategy, based on available bandwidth
LAN ports identified and labeled for SIP devices
WAN failover configured and tested, including failback

Network Configuration Recommendations

Create a dedicated voice VLAN to segment voice traffic.
Dedicate and label LAN ports to be used for phone devices
- If PCs are not piggybacking on phones you should set those ports as Access ports with the voice VLAN only
- If you are sharing a cable between phones and other equipment (like a PC or POS) you should set the port type to Trunk and make sure both VLANs are allowed on the port.
Create a DHCP scope for phones.
- Use a /24 network to accommodate for growth.
Yealink phones support LLDP and CDP
- This is the preferred method...let the router do the work!
Create and apply a QoS Policy that provides the highest level of priority for voice traffic. Tag all packets as EF.
- You can apply QoS to either the Voice VLAN, the voice subnet or RTP
Allow all traffic outbound from the voice VLAN
- Do not try to restrict outbound traffic as we may add servers, IP ranges and providers to our cloud service at any time
- If you are forced to whitelist outbound traffic, follow this guide to ensure phones will function: Setting Up Your Firewall for SimpleVoIP Service
- Set up policing and/or traffic throttling policies based on the actual tested bandwidth levels at each location (UP & DOWN).
- Without this your QoS policy may never kick in and becomes irrelevant
Normal operation off phones:
1. On bootup, they look for a redirect server at *.yealink.com or *.panasonic.com or *.polycom.com
2. Next they are redirected to our configuration server to download configs and firmware at https://config.simplevoip.us
3. Next they attempt to register with our SBCs at https://*.simplevoip.us