New High Availability Features in Lync 2010
DNS Load Balancing
Lync 2010 introduces DNS Load Balancing to provide high availability. As with other MS products, this provides application layer high availability instead of depending on hardware load balancers such as F5 or Cisco ACE. By creating DNS SRV records with different priority values, it allows administrators to load balance SIP and media traffic across servers. Back in OCS days, it only allowed a single _sipinternaltls._tcp SRV record per SIP domain. By implementing DNS load balancing, organizations can save money by not having to buy global load balancers.
Concept of Survivable Branch Appliances
This new concept allows organization to purchase appliances that run Lync 2010. SBA allows simplified deployment of dial plans and offer local services for a branch site. These appliances can integrate a PSTN gateway,Mediation Server, and Registrar. Localized services include:
- PSTN and other voice services
- Hold, retrieve, transfer
- Authentication and authorization
- Call forward, simul-ring, boss-admin, team-call
- Call detail records
- Intrasite IM and A/V
- PSTN audio conferencing