Page 88 - Part 1 IP Connectivity | How Do I? |
QoS over WAN between IPNC & 3rd Party Router
IPNC QoS is fully compliant with 3rd party router manufacturers that support Link fragmentation using PPP Multilink and IP Header compression (IPHC) (RFC
2507 and RFC 2508). This interoperation applies to both point to point and Frame Relay links using PPP encapsulation (see page 83).
All vendors that support a QoS mechanism on their routers will present their own method of voice traffic prioritisation to slow speed WAN links. The operation of such QoS mechanisms is “local” to a system but require that the enabling PPP protocols be negotiated on the link. IPNC will interoperate with any vendors QoS as long as the “enabling protocols” are agreed on the established link.
The “enabling protocols” for low speed WAN links are the PPP options for IP Header Compression (RFC 2508) and PPP Multilink (RFC1990). As long as these options are agreed on the PPP link (see The PPP Tab on page 52) then each router will “locally” apply QoS to their respective end of the link.
3rd party router interoperation relies on the successful negotiation of PPP protocol options (IPHC and Multilink). Once the PPP protocol options are agreed on the link both routers are then able to apply QoS polices to their respective ends of the link using fragmentation interleave and IP Header compression.
FTP Server
IP Phone_1C | IP Phone_2C |
192.168.123.101/24
192.168.123.1/24
INDeX 1
PPP Link (128k)
192.168.42.1/24
VPN
Router#1
Extns 1A & 1B | Extns 2A & 2B |
To configure QoS on an IPNC there are four mandatory parameters as shown below:
1.IP Header Compression set on the Service.
2.Multilink set on the service.
3.The WAN link configured for the WAN port speed.
4.An appropriate DSCP value system/gatekeeper tab
The IPNC 3.2 software has the following operating characteristics with respects to VoIP.
Description | Value |
Voice UDP port numbers range | OxC000 to 0xCFFF |
Signalling TCP port number | 1720 |
DSCP (TOS/Diffserv) value | 0xA0 |
The Configuration of the IPNC is dependant on the 3rd party router functionality. Use the quick WAN example as the basis for the configuration of interoperation and use the IPNC Monitor application to debug the PPP protocol exchange.
Page 88 - How Do I? | INDeX IPNC Cassette Administration Manual |
Part 1 IP Connectivity | 38DHB0002UKDD – Issue 7 (22/11/02) |
