- DSCP on layer2 SIP / Signalling: We tag all SIP / Signalling traffic between our session border controllers (SBC) towards our immediate upstream carriers and peers. For customers connecting via one of our layer2 Metro Voice that traffic is marked using DSCP – EF for RTP and AF31 for SIP signalling.
- Public Layer3: For customers attempting to set QoS markings leaving their routers most ISP’s as standard practise will explicitly remark the traffic as best efforts. Similarly any QoS markings leaving our network cannot be guaranteed over public internet services.
Telstra and Optus over NBN
Telstra and Optus customers connecting via NBN are reporting that QoS tagged traffic between specialist service providers and the customer is being blocked.
- Cause: NBN services are blocking differentiated services code point (DSCP) in the 8-bit Differentiated services Field (DS field) resulting in the loss of all communication between us, as the ITSP and the customer.
- Resolution: For customers on Telstra and Optus NBN IT admins must set any DSCP values to 0 to allow the traffic through NBN.
- Scope: While NBN’s layer3 tagging policy is known to impact Telstra and Optus customers we have not recorded any feedback from iiNet or TPG subscribers.
- Last updated: 19 Jan, 2016