Cisco Cisco Expressway Maintenance Manual
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H.323 calls, and interworked H.323 to SIP calls: the Disconnect command will actually disconnect the call.
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SIP to SIP calls: the Disconnect command will cause the Expressway to release all resources used for the call
and the call will appear on the system as disconnected. However, SIP calls are peer-to-peer and as a SIP
proxy the Expressway has no authority over the endpoints. Although releasing the resources may have the
side-effect of disconnecting the SIP call, it is also possible that the call signaling, media or both may stay up
(depending on the type of call being made). The call will not actually disconnect until the SIP endpoints
involved have also cleared their resources.
and the call will appear on the system as disconnected. However, SIP calls are peer-to-peer and as a SIP
proxy the Expressway has no authority over the endpoints. Although releasing the resources may have the
side-effect of disconnecting the SIP call, it is also possible that the call signaling, media or both may stay up
(depending on the type of call being made). The call will not actually disconnect until the SIP endpoints
involved have also cleared their resources.
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SIP calls via the B2BUA: as the B2BUA can control the state of a call, if you disconnect the leg of the call that
is passing through the B2BUA (where the Type is B2BUA), the call will fully disconnect. Note that the call may
take a few seconds to disappear from the Call status page — you may have to refresh the page on your
browser.
is passing through the B2BUA (where the Type is B2BUA), the call will fully disconnect. Note that the call may
take a few seconds to disappear from the Call status page — you may have to refresh the page on your
browser.
B2BUA Calls
The B2BUA calls page (Status > Calls > Calls or Status > Calls > History, then click View for a particular B2BUA call)
provides overview information about a call routed through the B2BUA.
provides overview information about a call routed through the B2BUA.
Calls are routed through the B2BUA if:
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support has been triggered
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is enabled and the call has been routed through the To Microsoft Lync
server via B2BUA neighbor zone
Note that for Microsoft Lync B2BUA calls, you can click the Corresponding Expressway call link to see details of the
leg passing through the Expressway.
leg passing through the Expressway.
Viewing B2BUA Call Media Details
page by clicking View media statistics for this call)
shows information about the media channels (audio and video) that made up the call passing through the B2BUA. For
calls using the Microsoft Lync B2BUA, this comprises legs between the Expressway, the Lync server and, if
applicable, the transcoder.
calls using the Microsoft Lync B2BUA, this comprises legs between the Expressway, the Lync server and, if
applicable, the transcoder.
Search History
The Search history page (Status > Search history) lists the most recent 255 searches that have taken place since
the Expressway was last restarted.
the Expressway was last restarted.
About searches
Before a call can be placed, the endpoint being called must be located. The Expressway sends and receives a series
of messages during its attempt to locate the endpoint being called; these messages are each known as searches. An
individual call can have one or more searches associated with it, and these searches can be of different types.
of messages during its attempt to locate the endpoint being called; these messages are each known as searches. An
individual call can have one or more searches associated with it, and these searches can be of different types.
The type of search message that is sent depends on whether the call is for SIP or H.323, and whether the call request
was received locally or from an external zone, as follows:
was received locally or from an external zone, as follows:
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H.323 calls that are placed locally: two messages are sent - the first is an ARQ which locates the device being
called, and the second is the call Setup which sends a request to the device asking it to accept the call. Each
message shows up as a separate search in the Search history page, but only the Setup message is
associated with a particular call.
called, and the second is the call Setup which sends a request to the device asking it to accept the call. Each
message shows up as a separate search in the Search history page, but only the Setup message is
associated with a particular call.
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H.323 searches originating from external zones: an LRQ will appear in the Search history page.
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SIP: a single message is sent in order to place a call: this is either a SIP INVITE or a SIP OPTIONS.
Note that an individual call can have one or more searches associated with it, and these searches can be of different
types. Each search has an individual Search ID; each call has an individual Call Tag (see
types. Each search has an individual Search ID; each call has an individual Call Tag (see
).
The Expressway supports up to 500 concurrent searches.
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Cisco Expressway Administrator Guide