| Call Records and Call Forwarded Telephone Numbers By George Molczan |
Call records associated with calls to or from call forwarded numbers can be misleading
and confusing. For example, Figure 1 is the result of a subpoena for incoming and
outgoing calls for telephone number 310-555-1678 (1678). Call record #1 shows there
was an incoming call to the target number at 13:45:14, which is correct. However, look
at call #2. It has the same start time as call #1, showing a call was made from the target
number (1678) to 310-555-2456 (2456). In this case a call was not placed from the
target number to the 2456 number. It was the call that generated record #1 being
forwarded to the 2456 number that generated call record #2.
Originating Terminating
The Date Time Number Number Duration
1 3/2/2006 13:45:14 204-567-1524 310-555-1678 63
2 3/2/2006 13:45:14 310-555-1678 310-555-2456 63
Figure 1 - Call Records Indicating a Call Forwarding Scenario
Key indicators of call forwarding
In this instance there are two key indicators that show that this is a call forward scenario:
- Both calls originate at the same time (13:45:14)
- Both calls have the same duration (63 seconds)
A second example is shown in Figure 2 shows call #2 starting 10 seconds after call #1.
In this case it is an indication 310-555-1678 has three-way calling or conference
capabilities. After answering call #1, the target number (1678) conferenced in the
number 310-555-2456. In theory both calls could still have the same duration, it would
be unlikely that the second call would have continued exactly 10 seconds past the time
where 1524 disconnected from the call. Even if both calls had the same duration, the
fact that they have different originating times is an indication that this is a three-way
calling or conferencing scenario not a call forwarding scenario.
Originating Terminating
The Date Time Number Number Duration
1 3/2/2006 13:45:14 204-567-1524 310-555-1678 63
2 3/2/2006 13:45:24 310-555-1678 310-555-2456 53
Figure 2 - Call Records Showing a Conferencing Scenario
If, in either example 310-555-2456 were the target number, only call record #2 would be
provided when subpoenaing the records from the telephone company. With just that
record there would be no indication that the call had been call forwarded or that it was
part of a conference or 3-way call.
If in doubt, how do you know for sure?
When working a case requiring proof a call was call forwarded, there is a process that
may help. Using the example in Figure 1, the telephone company that supplied the call
records may still have raw data or detailed records for the call. The raw/detailed
records provide details beyond what is shown in either figure 1 or 2 or typically supplied
as a response to a subpoena.
In the case of the example in Figure 1, getting the detailed records for call #2 would
indicate it was the result of a call forwarding action also known as Redirect in telephone
company lingo. The raw data block for call #1 in Figure 1, contains 83, 8 bit words of
data. Each bit or group of bits represents some facet of the call. For example, in this
case there is an indicator that tells the number searched (1678) was an ISDN line, the
call was not handled by an operator, it was not an international call and that the number
(1678) was set for an unconditional transfer or redirect. The raw data also includes the
number the call was transferred, in this case to (2456).
Convincing a telephone company that they may have additional information about a
call, could be a challenge. Retrieving the raw data for a call would likely be out of the
normal scope of work for a records custodian. Depending on the company size and
structure an IT analyst or a Network/Switch Engineer may have to be involved. If proof
that a call was "redirected" (forwarded) is important to a case, there is a way to get the
raw data.
Copyright © 2006 George Molczan, all right reserved.
The information provided herein should not be considered as legal advice. The reader is advised
to seek legal counsel regarding use and/or application of call records or any other information
provided herein.
The information provided herein should not be considered as legal advice. The reader is advised
to seek legal counsel regarding use and/or application of call records or any other information
provided herein.
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Last updated 03-17-06