thanks all
On Wed, Oct 19, 2011 at 2:05 PM, Brandon W. Yuille <b...@bwysystems.com>wrote:
> **
> Nope, as you see the callid field is defined as simply a word followed by
> an optional '@' with a trailing word. Just stick to the defined values that
> make up a word and you're all set.
>
> Since it seems you're looking for exact information then you should just
> read rfc 3261 rather than asking for help multiple times within 10 mins:
>
> 8.1.1.4 Call-ID
>
> The Call-ID header field acts as a unique identifier to group
> together a series of messages. It MUST be the same for all requests
> and responses sent by either UA in a dialog. It SHOULD be the same
> in each registration from a UA.
>
> In a new request created by a UAC outside of any dialog, the Call-ID
> header field MUST be selected by the UAC as a globally unique
> identifier over space and time unless overridden by method-specific
> behavior. All SIP UAs must have a means to guarantee that the Call-
> ID header fields they produce will not be inadvertently generated by
> any other UA. Note that when requests are retried after certain
> failure responses that solicit an amendment to a request (for
> example, a challenge for authentication), these retried requests are
> not considered new requests, and therefore do not need new Call-ID
> header fields; see Section 8.1.3.5.
>
> Use of cryptographically random identifiers (RFC 1750 [12]) in the
> generation of Call-IDs is RECOMMENDED. Implementations MAY use the
> form "localid@host". Call-IDs are case-sensitive and are simply
> compared byte-by-byte.
>
> Using cryptographically random identifiers provides some
> protection against session hijacking and reduces the likelihood of
> unintentional Call-ID collisions.
>
> No provisioning or human interface is required for the selection of
> the Call-ID header field value for a request.
>
> For further information on the Call-ID header field, see Section
> 20.8.
>
>
>
> Brandon
>
>
> On 10/19/2011 04:23 AM, Srikanth satturi wrote:
>
> This is the rule i saw in forums,
>
> From 3261:
>
> callid = word [ "@" word ]
>
> word = 1*(alphanum / "-" / "." / "!" / "%" / "*" /
> "_" / "+" / "`" / "'" / "~" /
> "(" / ")" / "<" / ">" /
> ":" / "\" / DQUOTE /
> "/" / "[" / "]" / "?" /
> "{" / "}" )
>
> alphanum = ALPHA / DIGIT
>
> All of the mechanisms specified in this document are described in
> both prose and an augmented Backus-Naur Form (BNF) defined in RFC
> 2234 [10]. Section 6.1 of RFC 2234 defines a set of core rules that
> are used by this specification, and not repeated here. Implementers
> need to be familiar with the notation and content of RFC 2234 in
> order to understand this specification. Certain basic rules are in
> uppercase, such as SP, LWS, HTAB, CRLF, DIGIT, ALPHA, etc. Angle
> brackets are used within definitions to clarify the use of rule
> names.
>
> So I thought theremay be a explicit rule defined for call-id generation
>
>
> Srikanth
>
> On Wed, Oct 19, 2011 at 1:02 PM, Brandon W. Yuille <b...@bwysystems.com>wrote:
>
>> Hi,
>>
>> The call id just needs to be a semi-unique identifier. The method for
>> generating this is application specific, so there are no requirements for
>> this value other than it should be unique in space and time. A common method
>> I see in many sip applications is to generate a random value most likely
>> also containing the current time concatenated with the ip address or host
>> address of the application that is generating the call id.
>>
>> Example: "Call-ID: 01234556789abc...@example.com" or "Call-ID:
>> 01234556789abcdef@192.168.1.2"
>>
>> In that example imagine 0123456789abcdef is a base 16 sudo random number
>> with a timestamp mixed in. You could use any base you'd like or come up with
>> any form of more uniqueness.
>>
>> Hope this helps,
>> Brandon
>>
>>
>> Srikanth satturi wrote:
>>
>> anyone please
>>
>> On Wed, Oct 19, 2011 at 12:40 PM, Srikanth satturi
>> <srikanth.satt...@gmail.com> wrote:
>>
>>
>>
>> Could please anyone help me out
>>
>>
>> On Wed, Oct 19, 2011 at 12:23 PM, Srikanth satturi
>> <srikanth.satt...@gmail.com> wrote:
>>
>>
>>
>> Could anyone please give me rules for sip call id generation, in RFC 3261
>> it is not clear, can i find specs anywhere. Please help me out
>>
>> --
>> Srikanth satturi
>>
>>
>>
>> --
>> Srikanth satturi
>>
>>
>>
>>
>
>
> --
> Srikanth satturi
>
>
--
Srikanth satturi
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