Chapter Nine, VoiceMail Pro in SCN Module One – Meshed Network with IPO

1. Chapter Nine,VoiceMail Pro in SCNModule One – Meshed Network with IPO

2. Small Community Network (SCN) Overview When connecting IP Offices together over IP or Packet based networks, Small Community Networking enhances feature transparency. These networks can support up to a maximum of 1000 users across 32 sites. • The following additional features are available:

3. SCN Requirements • For Small Community Networks VCM modules are required in all systems being connected. • The IP lines may be configured in a star or a meshed configuration. • Each IP Office system broadcasts UDP messages on Port 50795. • SCN is supported between IP Office systems with the same major software level or one level of difference in major software level. For example between 4.2 and 4.1 (same major level) and between 5.0 and 4.2 (one major level of difference). • If larger networks are required QSIG can be used to link multiple Small Community Networks together. Functionality between the communities is governed by the QSIG feature set.

4. SCN Requirements - continued • QSIG, H.323 and SCN capabilities are not enabled by default in the IP500 and IP500v2. • On IP500 and IP500v2 systems Small Community Networking requires one or more additional licenses. • An additional license is required to enable this functionality with 4 simultaneous networking channels. • Additional channels can then be licensed in increments of 4. • A Voice Networking license is required to enable TDM QSIG, even though there is no limit to the number of TDM QSIG calls that can be made or received once licensed.

5. Supported SCN Configuration: Star / Serial • The following are examples of star and serial layouts. These are the only types of layouts supported for Small Community Networks containing any pre-IP Office Release 5 systems. • The IP network supporting the SCN may be ‘meshed’, but the IP Office configuration must use a star, serial or a star / serial combination configuration.

6. Supported SCN Configuration: Meshed • The use of 'mesh' layout connections is supported for a Small Community Network beginning with IP Office Release 5. • A mesh layout contains H.323 SCN Line routes between two or more IP Office control units. • Mesh, star and serial layouts can be combined.

7. Protocol Considerations When deploying IP Office in a meshed environment there are some common protocols that may deployed to support the IP Network supporting the SCN: • Spanning Tree Protocol (STP): Layer 2 protocol that allows for network connection redundancy while preventing physical loops. • Multiprotocol Label Switching (MPLS): is a highly scalable, protocol agnostic, data-carrying mechanism where data packets are assigned labels and packet-forwarding decisions are made solely on the contents of this label. MPLS is often referred to as a "Layer 2.5" protocol. • Open Shortest Path First (OSPF): is a Layer 3 “link-state” routing protocol and is perhaps the most widely-used protocol in enterprise networks.

8. Routing Information Protocol (RIP) RIP is a simple method for automatic route sharing and updating within small networks. It allows alternate routes to be advertised when an existing route fails. • IP Office systems can utilize RIP on LAN1, LAN2 and individual services with the following options: • Listen Only (Passive): Listen to RIP1 and RIP2 messages and update the routing table, do not advertise routes. • RIP1: Listen to RIP1 and RIP2 messages and advertises routes in a RIP1 sub-network broadcast. • RIP2 Broadcast (RIP1 Compatibility): Listen to RIP1 and RIP2 messages and advertise routes in a RIP2 sub-network broadcast. • RIP2 Multicast: Listen to RIP1 and RIP2 messages and advertise routes to the RIP2 multicast address (249.0.0.0).

9. Network Address Translation (NAT) NAT is the process of modifying network address information in IP packet headers while in transit through a router for the purpose of remapping a given address space into another. • NAT is useful as internally most networks use addresses that have been reserved for public use within networks but are not valid for routing across the internet and it allows multiple users to use the same address simultaneously (PNAT). • IP Office can use NAT on the LAN1 and LAN2 (WAN) interfaces to support data services and lines / trunks: H323 Line, IP DECT Line, SIP Line and SES Line. • The Static NAT table in the IP Office Firewall allows address translation between up to 64 selected internal and external IP address pairs.

10. Private Address Space The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP address space for private internets: An enterprise that decides to use IP addresses as listed above can do so without any coordination with IANA or an Internet registry.

11. SCN Signaling Within an SCN the separate IP Office systems 'learn' each other's extension numbers and user names. • IP Office SCN uses a signaling similar to RIP is order to update each other of there presence. This traffic can be seen in the IP Office System Monitor application as AVRIP packets. • Each IP Office system ‘listens’ for AVRIP traffic on port 50795. • Each IP Office in the SCN transmits an update every 30 seconds. • Additionally BLF updates are transmitted when applicable up to a maximum of every 0.5 seconds. Typically the volume is less than 1Kbps per IP Office system.

12. SCN Configuration Requirements • To set up a small community network, the following are required: • H323 trunk(s) between the IP Office systems (H323 Line) • On IP500 and IP500v2 systems, H323 trunks require the entry of IP500 Voice Networking licenses • Data routing between IP Office systems (IP Route) • The extension, user and group numbering on each system must be unique. • The user and group names on each system must be unique. • All systems should use the same set of telephony timers, especially the Default No Answer Time. • Avaya recommends that all names and numbers (line, services, etc) on the separate IP Office systems are unique.

13. Bandwidth Calculator

14. H323 Trunk Configuration

15. Three Site SCN Example • The table below shows the H323 Trunk configuration options for a three site SCN with a meshed configuration.

16. IP Office SCN - Fallback • IP Office Release 5 provides a number of features that allows IP Offices to provide fallback functions for each other. • Each IP Office in the SCN can include one H323 line where the Supplementary Services is set to IP Office SCN – Fallback. • Once a line is set to IP Office SCN - Fallback, the following options are available: • Backs up my IP Phones • Backs up my Hunt Groups • Backs up my Voicemail • Fallback is only intended to provide basic call functionality if the IP Office is not visible within the SCN for a period of more than 3 minutes.

17. IP Route Settings • When an IP Office needs to send data to IP addresses on a different subnet, for example another IP Office in a Small Community Network (SCN), the IP Route table is used by the IP Office to determine where data traffic should be forwarded. • This is done by matching details of the destination IP address to IP Route entries and then using the Destination specified by the matching IP route. These are referred to as 'static routes'.

18. Three Site SCN Example • The table below shows the IP Route configuration options for a three site SCN with a meshed configuration.