Ports IPs and our Network


Proxy call.sipcity.com.au
TCP/TLS Proxy call.sipcity.com.au port 5061
SIP Peering
SIP Registration (call.sipcity.com.au)
SIP Port – UDP 5060
SIP Port – TLS 5061 (ensure transport = TLS)
Firewall IP Range
Number 63971

Other ports

RTP and UDPTL Set by your router (our port range is 30,000 – 40,000)
t.38 (faxing) 4000-6000
Fax fax.sipcity.com.au
Primary NTP au.pool.ntp.org

Overview of our physical setup

Our Australia DC is located in the Equinix SY4 internet exchange in Sydney with failover to our US data centre in Los Angeles. All services are deployed against Proxmox VE containers with data held against a distributed CEPH storage cluster. All core systems including phone, video, fax and messaging therefore deployed across HA containers, apart from the database which is an InnoDB cluster mounted on LXC containers with their own separate SSD storage.

IP Transit

For customers connecting over the public internet, we advertise our assigned IP via BG using Vocus and TPG internet transit.


We use the Megaport IX to connect with Australian ISP’s whom we are unable to directly peer with namely Optus and Telstra. 

What’s the difference between UDP & TCP

UDP and TCP SIP are both used to send data over the Internet or a local network with UDP being older but more common protocol and TCP with its guarantees of transmission the more modern & preferred protocol for companies like Microsoft. While UDP is the more efficient transport for service providers and customers alike — we still prefer TCP because packet transmission and order is guaranteed and with modern internet speeds and CPU processing power the costs of TCP in our view are academic.

We support both UDP and TCP.

Real-Time Protocol (RTP)

RTP is the protocol used to deliver audio and video over IP networks. RTP uses the UDP protocol because its efficient in low-quality networks such as phones communicating over the public internet. (NB – while your router sets the specific RTP port, we will accept communication between the 30-40k range).

TLS Support

While most VoIP service providers recommend disabling SIP ALG on customers routers, we recommend setting TLS over port 5061 as the alternate and more resilient mechanism to prevent unauthorised firewall intrusion.


We support Secure RTP connections from devices that support the protocol. SRTP allows for secure transmission of the media/audio stream for deployments that require increased security.

See also How Secure is YourCloudPBX Business VoIP?

Do we support QoS?

Yes; while we support QoS for our direct Cross-Connect customers and partners, Australian ISPs by default remark QoS rules as Best Efforts over the public internet.From our side we mark our SIP/RTP Voice Services with the following QoS rules up to our IP transit provider:

SIP is marked as DSCP value of AF31
RTP (media) and Fax payload is marked as DSCP value of EF
All other traffic – web portal access etc is marked as DSCP value of Best Efforts
NB – IP phones as trusted end points by default will usually mark the packets correctly, however when connecting via switch ports on a Cisco for example you’d normally need to enable following interface: mls qos trust dscp.

Telstra NBN Services

Telstra are blocking all class of service (QoS) on their NBN services which will prevent Registration or Peering to our platform. To enable registration on a Telstra NBN service simply disable DSCP (see below).

Set IP DSCP (overrides IP ToS) to a value of 0.

Updated on 20 October 2021

Related Articles