SIP
For businesses with existing systems (ISDN2 or ISDN30), SIP offers a high quality, lower cost solution. By 2020 it is forecast that SIP & Hosted VOIP will overtake ISDN as the preferred method of business communication.
If you have no form of existing digital system, then you may want to consider our Hosted VOIP Telephony
So what is SIP? This stands for Session Initiation Protocol. You may have seen some confusing or overly complex diagrams explain what SIP is and how it works; the below keeps things simple and factual.
Assuming you do have some form of ISDN phone system, there are 4 main component parts that you will have now:
The ISDN box – this is a small box that will be located near a standard BT phone socket (exactly like you would see in a domestic home). This will allow you to make or receive a certain number of simultaneous calls. The number of lines your ISDN supports are called “Channels”. An ISDN2 can support up to 8 channels; an ISDN 30 can support up to 30 channels. You can have as many ISDN boxes as your business needs (so if you wanted 60 channels, you would need 2 ISDN30’s).
Second is your switch. A switch is a large splitter; put simply 1 wire goes from your ISDN box into your switch, and many wires come out of it to plug into your phones.
3rd is your PBX. If you image a human body: the ISDN is the arms and legs doing the physical carrying (in this case calls). The PBX is the brain; it decides what extensions to call when someone rings into your business, how to handle engaged lines, whether or not to show you your caller ID when you call someone etc. A PBX is similar in size and shape to a modern DVD player, and typically sits near your ISDN box. It will plug into your switch, and through this be able to control both the ISDN and the phones. Depending on the age of your system, the PBX may act as both PBX and Switch
Lastly is your end user hardware (the phones that people use). These will be plugged into your switch via cables, and through this access your ISDN
If you choose a Hosted Telephony Solution it is highly likely that you would need to change your existing phones as they would not be compatible with VOIP (unless you are already using VOIP). The reason for this is that your ISDN and PBX would become obsolete as these would now be hosted by us “in the cloud” (a cliché term we appreciate). For first time system purchases, Hosted Telephony is usually the way to go depending on the size of the requirement. For many systems (10 channels or less) – Hosted Telephony is still likely to prove cheaper.
If you did go for Hosted Telephony, your existing Digital phones would not be able to speak to a VOIP PBX (cloud based). Enter SIP: SIP works by re-programming your PBX to point at our servers and data centre rather than your current suppliers.
This means that for all intents and purposes, your ISDN box becomes redundant (we have a version of this in the cloud). However as your PBX is still in place, your phones can still speak to it, meaning that you keep all your existing phones.
The advantage of SIP is that you get VOIP rates and rental prices which can be far less than ISDN or analogue.
Re-programming of a PBX is a specialist job, and not all PBX’s will be enabled for VOIP (IP-PBX Compatibility). If you are considering SIP as an option, it is highly recommended that you call us to discuss this. We will need the current make, model and supplier of your hardware (ISDN and PBX). We will also need your main ISDN number and your business postcode. From this we can tell you if you can move to SIP with your current PBX. If you cannot, then you have two options:
- Buy an IP-PBX to replace your existing one (prices start at around £800 and can move to £3,000+ depending upon requirements)
- Investigate Hosted Telephony with us (just buy new phones and we host all your hardware).
Why Use Our SIP Trunks
Saffwood’s business VoIP service is a secure connection between your SIP PBX and our network to allow your telephone calls to be placed. Calls reach our network and they are routed to a carrier eg BT. The service is provided to you with a number of channels for inbound and outbound calling. Saffwood is a publicly accessible telephone service (PATS) provider and as such it provides any UK numbers, emergency services, number porting, international calls and many other services.
Saffwood’s business VoIP service is ideal for large organisations for the following reasons:
Quality of the service - Voip services are generally classified into Platinum, Gold and Silver categories with the quality of service reducing respectively. A silver service can look commercially appealing but the calls may be routed internationally before reaching your UK phone. Sometimes Silver services do not consistently present caller line ID (CLID), this is a breach of Ofcom regulations for call centres. The call quality can be patchy and have latency (delay) between the called and caller. Saffwood always provides a high quality voip service unless requested specifically to lower the quality in favour of price.
Failover - Saffwood peers with multiple carriers and can continue terminating calls seemlessly or with little downtime, in the event that carrier route fails.A softswitch is required to do this, Saffwood has two of them in separate data centres. Softswitches aggregate carrier routes and can load balance between them. This is necessary for resilience but also to manage the calls per second rate. Pushing traffic through carriers with high rates of calls per second can lead to you being suspended. Carriers do not like bursty traffic because it can make their gateways freeze which would affect lots of their clients.
Designed for Business - VoIP service providers measure their performance based on two main targets; Average Call Duration (ACD) and Answer-Seizure Ratio (ASR). Call centre VoIP traffic generally delivers low call duration and low answer rate, this is not popular with most carriers. Hostcom has designed its network and uses its load balancing capabilities to ensure that all carriers receive satisfactory ACD and ASR rates.
Location of gateways - If you are calling in the UK the voip service provider should have gateways or softswitches located in the UK at multiple locations. This is necessary to ensure that latency is kept to a minimum and also to ensure that CLI is presented correctly to the called party. If the gateways are not in the UK the caller ID may present to the called party in full international format which can be confusing.
Secure connectivity - the service provider should be able to furnish you with a security policy stating how they secure their service. Telecoms fraud is very common and can lead to a significant losses if you dont get the right advice. Saffwood has many security measures in place to lock out unauthorised use of your business VoIP service such as IP address authentication, custom A-Z tariff sheets, time of day call blocking and fraud monitoring. We also have the in-house expertise to help you secure your PBX.
PBX experience - Saffwood has years of experience with Cisco and Asterisk PBXs and it can provide you with assistance in the setting up of a trunk with all major service providers including Avaya, Mitel, FreeSwitch, Vicidial, 3CX and Microsoft Lync.
