How to extend NLA ID into reserved field

[Yann-Ju Chu]

We have got one subTLA block and 
if  I futher divide my subTLA as following:

             1/35   1/39   1/43   1/48
     ---------+------+-----+------+--------------
     | subTLA | NLA1 | RES | NLA2 |             |
     ---------+------+-----+------+-------------
I assign NLA2 to my directly connected customers. And I have confusion about how
to use RES bit for my NLA2.

There is one line in RFC2374 talking about how to use RES for NAL2:
To extend the NLA ID into the reserved field if additional room for complexity is needed.

When I have consumes all NLA2 for a given (subTLA, NLA1, RES=0) pair and now some of my
customer need more address from me, If I extend the NLA2 ID into the reserve 
field, the address for the customer seems not to be continuous. (The previous and the
new one I assinged) . With the condition, I would rather allocate another NLA1
to assign NLA2.

Can anybody tell me what's the above line means? 
(To extend the NLA ID into the reserved field if additional room for complexity is needed.)
 					Thanks


-- 
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      Yann-Ju Chu
    Telecommunication Laboratories
    ChungHwa Telecom Co., Ltd.
    TEL: +886 3 424-5681
    FAX: +886 3 424-4888
    http://www.chttl.com.tw
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