Non-stop VoIP support
View Patent ↗A packet switch collects configuration information on the peer devices to which it connects. Peer devices that are IP (Internet Protocol) telephones are sensed. Such devices may also bridge packets to a connected device such as a computer, but with a bridge capability that cannot handle large broadcast storms on the network. The packet switch uses the configuration information to limit broadcast storms on its ports connected to the relatively fragile IP telephones/bridges. This can prevent broadcast storms from disrupting calls on the IP telephones connected to the packet switch.
1. A method of operating a packet switch, the method comprising:
periodically collecting information on peer capabilities for a plurality of peer devices each connected respectively to at least one of a plurality of external ports of the packet switch, the collected information received via Link Layer Discovery Protocol (LLDP) packets and including information indicating a packet-based telephone capability for the peer devices;
determining, for peer devices associated with information indicating the packet-based telephone capability, whether a bridge is being provided for a downstream device;
configuring at least one packet processing device on the packet switch to limit broadcast packet traffic on at least one external port of the packet switch, the broadcast packet traffic limit including a first broadcast packet traffic limit in response to the collected information indicating that the peer device connected to the at least one external port contains a packet-based telephone capability, and the broadcast packet traffic limit including a second broadcast packet traffic limit in response to determining the peer device contains a packet-based telephone capability and is providing a bridge for a downstream device; and
snooping packets and detecting the recent presence of voice data packets resulting from a first peer device being associated with an active call and, in response, dynamically changing the broadcast packet traffic limit of the first peer device to the first broadcast packet traffic limit when the first peer device contains a packet-based telephone capability and is engaged in the active call, and dynamically changing the broadcast packet traffic limit to the second broadcast packet traffic limit when the first peer device contains a packet-based telephone capability and is providing a bridge for a downstream device that is engaged in the active call.
2. The method of claim 1 , wherein collecting information on peer capabilities comprises receiving advertisements from the peer devices, interpreting the contents of the advertisements to determine the peer capabilities, and storing the interpreted contents in a data structure.
3. The method of claim 2 , wherein the received advertisements are LLDP packets having a plurality of type-length-value fields (TLVs) in each such packet.
4. The method of claim 3 , wherein at least one TLV indicates functions of the peer device transmitting the advertisement, including whether the functions exist in the peer device and whether the existing functions are currently enabled.
5. The method of claim 3 , wherein at least one TLV contains an organizationally-unique identifier and corresponding content, the corresponding content indicating a broadcast packet traffic limit requested by the peer device transmitting the advertisement.
6. The method of claim 3 , wherein at least one TLV indicates an endpoint type, and wherein collecting information comprises parsing the endpoint type to determine whether the peer device transmitting the advertisement contains a packet-based telephone capability.
7. The method of claim 1 , wherein collecting information on peer capabilities comprises snooping packets passing through the packet switch, the packets addressed to or from at least one of the peer devices, inferring from the contents of at least one header in one of the snooped packets a packet-based telephone capability for the peer device addressed in the snooped packet, and storing the inferred packet-based telephone capability for the peer device in a data structure.
8. The method of claim 7 , wherein the snooped packets comprise at least one selected packet type from the group of packet types consisting of: packets addressed to or from a call setup gatekeeper; call signaling and setup packet addressed to a telephone peer device; audio data packets; video data packets; and combinations thereof.
9. The method of claim 1 , further comprising interrogating at least one of the peer devices to cause the peer device to send, to the packet switch, information on peer capabilities.
10. The method of claim 1 , wherein collecting information comprises periodically monitoring LLDP packets passing through at least one of the plurality of external ports for changes in the status of the peer device connected to that port.
11. The method of claim 10 , wherein the broadcast packet traffic limit for the first peer device is modified for the duration of the active call.
12. The method of claim 1 , wherein the determination that a bridge is being provided to the downstream device includes the collected information further including information indicating a bridge capability for the peer devices.
13. The method of claim 1 , wherein the first broadcast packet traffic limit for the peer device that has a packet-based telephone capability but no bridge capability includes an endpoint-level broadcast storm control, and the second broadcast packet traffic limit for a peer device that has a packet-based telephone capability and a bridge capability includes a bridge-level broadcast storm control.
14. The method of claim 1 , wherein setting of the second broadcast traffic limit further depends on whether the packet-based telephone capability and the bridge capability are enabled on a peer device.
15. The method of claim 12 , wherein information indicating a bridge capability for a given one of the peer devices includes information indicating that the given one of the peer device is actually bridging packets for another device.
16. The method of claim 15 , wherein configuring at least one packet processing device on the packet switch to limit broadcast packet traffic comprises, when the given one of the peer devices receives telephone packets on a first virtual local area network and bridged packets on a second virtual local area network, setting different broadcast packet traffic limits for the given one of the peer devices, depending on the virtual local area network on which the packet traffic is broadcast.
17. The method of claim 1 , wherein limiting broadcast packet traffic comprises limiting at least one type of broadcast packet and not limiting at least one other type of broadcast packet.
18. An apparatus comprising a non-transitory, computer-readable medium containing computer instructions that, when executed by a packet switch comprising one or more processors, cause the packet switch to perform a method comprising:
periodically collecting information on peer capabilities for a plurality of peer devices each connected respectively to at least one of a plurality of external ports of the packet switch, the collected information received via Link Layer Discovery Protocol (LLDP) packets and including information indicating a packet-based telephone capability for the peer devices;
determining, for peer devices associated with information indicating the packet-based telephone capability, whether a bridge is being provided for a downstream device;
configuring at least one packet processing device on the packet switch to limit broadcast packet traffic on at least one external port of the packet switch, the broadcast packet traffic limit including a first broadcast packet traffic limit in response to the collected information indicating that the peer device connected to the at least one external port contains a packet-based telephone capability, and the broadcast packet traffic limit including a second broadcast packet traffic limit in response to determining the peer device contains a packet-based telephone capability and is providing a bridge for a downstream device; and
snooping packets and detecting the recent presence of voice data packets resulting from a first peer device being associated with an active call and, in response, dynamically changing the broadcast packet traffic limit of the first peer device to the first broadcast packet traffic limit when the first peer device contains a packet-based telephone capability and is engaged in the active call, and dynamically changing the broadcast packet traffic limit to the second broadcast packet traffic limit when the first peer device contains a packet-based telephone capability and is providing a bridge for a downstream device that is engaged in the active call.
19. A modular packet switch comprising:
a plurality of external ports;
a switch controller that periodically collects information on peer capabilities of peer devices connected to the plurality of external ports, the collected information received via Link Layer Discovery Protocol (LLDP) packets and including information indicating a packet-based telephone capability for the peer devices and a bridge capability of the peer devices; and
at least one packet processor to process packets sent out on the plurality of external ports, at least one of the packet processors having a per-port broadcast packet traffic limit facility, the switch controller selectively activating the per-port broadcast traffic limit facility for at least one of the plurality of external ports, the activated per-port broadcast traffic limit facility including a first broadcast packet traffic limit in response to collected information indicating that the peer device connected to that external port has a packet-based telephone capability, and the activated per-port broadcast traffic limit facility including a second broadcast packet traffic limit in response to determining the peer device contains a packet-based telephone capability and is providing a bridge for a downstream device;
wherein the switch controller snoops packets and detects the recent presence of voice data packets resulting from a first peer device being associated with an active call and, in response, dynamically changes the broadcast packet traffic limit of the first peer device to the first broadcast packet traffic limit when the first peer device contains a packet-based telephone capability and is engaged in the active call, and dynamically changes the broadcast packet traffic limit to the second broadcast packet traffic limit when the first peer device contains a packet-based telephone capability and is providing a bridge for a downstream device that is engaged in the active call.
20. The modular packet switch of claim 19 , wherein the broadcast packet traffic limit facility allows multiple levels of broadcast packet traffic limits, the switch controller selectively activating one of the levels of broadcast packet traffic limits based on specific collected information on the peer device having the packet-based telephone capability.
21. The modular packet switch of claim 20 , wherein the specific collected information includes a collected peer characteristic selected from the group of characteristics consisting of: an enabled-bridge status; a connected-bridge status; the presence of an active call on the peer device; an organizationally-unique advertisement corresponding to a given level of broadcast traffic limit; an endpoint type; the assignment of multiple virtual local area network identifiers to the external port linked to the peer device; and combinations thereof.