The simple answer is that it does not. If you don't specify a session timeout, the session will not timeout. This is how we run our PPPoE services. The protocol and BAS designer does not set the parameter - the network operator does. At 05:10 AM 30/05/2013, Joe wrote:

hi. a question obsessed me for a long time. "why my pppoe connection to internet has a max session time, even if every thing goes ok? " In our DSL access network , max session timeout is set to 4 days, this parameter is sent to BAS by radius server after finishing authenticating procedure. As I know, beside us some other service providers also applied this parameter to pppoe session, the parameter varies from 48 hours to 96 hours. Reading documents of BAS, we found this is default value for session-time on BAS, that means even if radius server does not response BAS with session-timeout attribute BAS will cut pppoe session after sometime. so , why does those BAS designer or protocol designer set such a parameter for pppoe access ? should anyone do me a favor on explaining this ? regards Joe

--- Clayton Zekelman Managed Network Systems Inc. (MNSi) 3363 Tecumseh Rd. E Windsor, Ontario N8W 1H4 tel. 519-985-8410 fax. 519-985-8409

On Thu, 30 May 2013 09:10:21 -0000, Joe said:

a question obsessed me for a long time. "why my pppoe connection to internet has a max session time, even if every thing goes ok? "

From a provider's point of view, forcing a connection to re-establish itself every few days means that if you ever have to roll out a change, you don't end up with *That* *One* *User* who stays connected for weeks or even months with the old parameters.

On 13-05-30 05:10, Joe wrote:

a question obsessed me for a long time. "why my pppoe connection to internet has a max session time, even if every thing goes ok? " In our DSL access network , max session timeout is set to 4 days, this parameter is sent to BAS by radius server after finishing authenticating procedure. As I know, beside us some other service providers also applied this parameter to pppoe session, the parameter varies from 48 hours to 96 hours. Reading documents of BAS, we found this is default value for session-time on BAS, that means even if radius server does not response BAS with session-timeout attribute BAS will cut pppoe session after sometime. so , why does those BAS designer or protocol designer set such a parameter for pppoe access ? should anyone do me a favor on explaining this ?

Under normal circumstances, usage accounting data is only sent when the PPPoE connection ends. So an ISP might want to force PPPoE sessions to end every couple of days to capture usage data for accounting/billing purposes. Note that there are techniques to get the BAS (or router) to send these accounting updates to the radius server at regular intervals, allowing uninterruoted PPPoE sessions. Not all ISPs may have implemented this. In Canada, when threathened with UBB and now morphed into CBB billing regime for wholesale, many ISPs read their router's manuals and found the way to get the forced sending of accounting data at regular intervals. This has allowed them for instance to provide for unlimited usage during the wee hours of morning. They get the routers to send out accounting info at 02:00 in morning and at 12:00 (noon) and the ISP can then count only the usage between noon and 02:00.