Inbound Calls and Availability Zones

Many of our customers connect to us in multiple sites, using SRV and DNS to load-balance between their sites.

We noticed, however, that some customers load-balancing between two sites 50/50 found that 50% of calls entering, say, Slough, were being sent across our network to their equipment in London, and vice-versa. Failover worked as it should but this isn’t efficient.

Accordingly, there is now a new option within the portal and API to configure SIP endpoints that are specific to a specific Simwood Availability Zone.

It is important to note these are not forcing inbound traffic to a specific site, but rather configuring how it is handled if it lands there.

These act as overrides, allowing customers with equipment in, for example, London, to ensure that any calls that ingress our network in London are delivered to the London equipment.

Where there is a zone-specific endpoint configured, other SIP endpoints at the same level will be ignored, however these will still continue to be used if a call reaches any other zone.

It’s imperative, therefore, to ensure that some non-zone-specific rules remain. The portal and API will prevent a configuration where this is not the case as otherwise calls would fail if they entered our network at a point that didn’t have a specific configuration.

NB This is an advanced feature, and the majority of customers who are not directly connected will not need to configure it, nor be concerned about it. For those who are directly connected, or have a geographically diverse infrastructure such as our own, this provides important flexibility and improved efficiency.